Gloryholes are rumored to be found in the backs of dirty book stores, or between the booths in peepshows and whatnot.
There are no rules because they aren't supposed to be there in the first place. It's just a hole made in the wall, and strangers use them to get blowjobs.
I've always assumed that they are very rare in real life, and mainly exist in pornography. It sounds like a really risky business, considering you have no idea who is on the other side of the wall.
If you could reduce the risk of disease to nil, then maybe it would be exciting
