I'll start by saying in spite of the fact I DO NOT recommend large volume electrolysis to anyone who doesn't strictly need it (i.e. you have hair that makes you a poor candidate for laser), I don't regret doing what I did. My results have been good, I have no scarring, and all of the aestheticians I saw were wonderful people looking to help trans women. That said, it is not a good use of your time or money. If you can do laser, you should do laser. The reduction laser gives you will be permanent, and you can skip doing laser maintenance appointments and just start doing electrolysis at that time. You will have a hairless face much faster and much cheaper than large volume electrolysis. Also note that while many specifics of my experience are particular to doing this procedure in Chicago with Cirine, I don't think any of the other places which offer sedation/large volume electrolysis do so in a way that would makeup for the numerous downsides.

What Actually Happens the Day of and How to Prepare

They do at least tell you this, but I will stress again the importance of eating a reasonable (but not too big) breakfast before your appointment. My second session I had only a bowl of oatmeal and found myself about to pass out as I sat up to drink gatorade a few hours in. I'd say oatmeal + a yogurt was enough for me as someone who generally only eats a bowl of oatmeal for breakfast. Wear extremely comfortable pants that you're okay sweating in for 8 hours, and a shirt has a loose enough neck hole you can avoid touching your face with the fabric. Do not bother wearing anything nice.

If you're traveling in from out of town, it is vital you do so with a second person. You will not be able to take proper care of yourself, and especially after the first appointment you will likely be shocked at how much swelling there is. I might've had it worse than most, but I was unable to open my jaw enough to eat proper food for 1-3 days after my appointments, so I lived on very calorie dense smoothies. Even if you don't have to travel from out of town, I would still recommend having a close friend or family member who can help you the day of the procedure and the day after (as the morning after the appointment will be the worst it gets, since the fluid will accumulate in your face as you sleep). I was in town so I can't give a good estimate as to when flying would be okay, but I would plan for 5 days after the appointment, especially the first one given how awful your swelling could be.

Odds are your appointment will start at 5am or around noon. I recommend having a pair of wireless earbuds (even if you're a boomer like me who prefers wired generally) and an external battery for your phone, as even though you'll be slipping in and out of consciousness at times it will make your time vastly less bad to have stuff to listen to for 8 hours (plus you should be SURE you have phone battery to call your ride).

After you're let into the room for the treatment, you'll change out of your shirt and into a gown, they'll put numbing cream on your face (frankly the smell of the alcohol might be the worst part of the procedure), the doctor or a nurse will come in to give you an IV to put you into a twilight state, then you'll get multiple injections of nerve blockers into your face (which hurt like a bitch, probably 6-7/10 on the pain scale).

What sadly none of the preparation emails tell you before hand is during the procedure your face will be mostly paralyzed after the nerve blockers are injected into your face. This means that even drinking water/gatorade will be a challenge since your lips won't close to create a seal, so I recommend bringing a tiny plastic cup from a cough syrup bottle, and drinking from that. My recommended technique is to pour the liquid into your mouth, then pinch your lips closed with your fingers so you can swallow. Because your face is numb you also won't know if you chew on your own cheeks/tongue, so I recommend only bringing yogurt or kefir for a snack. You WILL need a snack to keep your blood sugar high enough to avoid passing out in the middle of the procedure. Also MAKE SURE TO TAKE BREAKS. If you only take breaks when you have to pee, you WILL be at a higher risk of passing out. Pace yourself and make sure to regularly drink gatorade and kefir/yogurt.

Aftermath

Note that my experience was probably on the worse side of how these appointments can go, but there's really no way to know how you'll react beforehand. I followed every post op instruction to the letter and I still had a very rough go of it for my first 4-5 appointments. Also note that the appointments do get easier, you not only learn the ways your body will react, the affects are also just less intense the thinner your hair is and the less of it you have.

I've touched on this a bit above, but honestly if you get it as badly as I did I really cannot prepare you for the swelling. The worst part is on top of how swollen you are, your skin will ooze a bit in areas where your hair growth was thicker. Neosporin and the lotion they recommend you will be your friend. After the first day or so Aquaphor won't cause whiteheads, so use that too. Your partner/family member/friend will hopefully be with you through all of this, as you might have an anxiety attack as you look in the mirror. If you work in person (and especially if you do any physically strenuous work), I would be prepared to take at least 3 days off (and frankly I would position those by a weekend so you have those 2 days to recover as well, giving you a 5 day buffer). I work remotely and I still needed to take 2 days off for the first 2 appointments, and I definitely was in no shape to go anywhere or do anything for 4-5 days afterwards. Most importantly you should make sure you can avoid direct sun, your skin will be extremely damaged and you have to be careful to treat it delicately until the irritation subsides. It will make a full recovery, but you have to treat it correctly.

Cost

This is not a cheap way to get rid of your facial hair. I think all of my sessions cost me around $15k by the end of it, which was an expense I had budgeted for but frankly was not one I needed to. The 12 laser sessions you'd need to get those results* would cost 10% of that. Were it more convenient or less painful than laser, I could possibly recommend it to anyone who was a candidate for laser, but it is emphatically neither of those things. If you have a lot of coarse blonde hair, this is probably the least bad way to get your facial hair removed though.

*Large volume will not finish you up, you'll have to do traditional electrolysis appointments every 6ish weeks for likely around 6-8 months afterwards. For laser you of course will only get permanent reduction, but the traditional electrolysis you'd need after laser reduction is I would think at worst comparable.

Final thoughts

I would be remiss to leave out that the medical center in Chicago the procedure takes place in is mediocre at best. Despite scheduling your appointment months in advance, you will usually only learn what time to show up the day before, and over the course of my ~7 sessions I never once received my appointment time more than 48 hours in advance (once the time was changed on me the night before at 10pm - far too late when I was supposed to be there at 5am). This is NOT the fault of Cirine - the aestheticians are always prompt - it is the fault of the doctor. The doctor who actually administers the injections and applies the sedation (who I will not name because they Google themselves - you can easily search yourself to find out who I mean) is very unprofessional - before my first appointment I could hear them cursing out one of the nurses, and while I didn't experience any of the horror stories you read online having met him I fully believe that many of them are true. I would trust this doctor with injections and literally nothing else. The center is also not well staffed - after my first appointment I was left alone to wait for the woman who does the lymphatic drainage massage, and during that time I nearly passed out and found no one to help me. I thankfully was okay, but you should make sure you have a friend or family member present AT the center once it gets close to the end of your appointment, because there might not be anyone else there to help you should the worst happen.

Overall 6/10 experience, at least my facial hair's gone forever!