There's no catch, what you've presumed is correct. The last one I went to was called The King George.
External Link/Members OnlyYou pay a flat rate to go in and enter a bar area with slightly dated decor (which makes it appealing if you like that sort of thing). There are stools at the bar, booths with seating and also a few fruit machines around (which some bored girls seemed to spend too much time on!).
Soft drinks are free (flat cola poured from a plastic bottle) or you can pay for alcoholic drinks. The girls might try and persuade you to buy them a drink because they get a kickback, but this isn't a hard sell, they'll simply say "would you like to buy me a drink?". Simply reply "I'm OK but you're welcome to join me if you like".
When I was there it was extremely quiet. There were about 4 girls working. 2 of them I can't remember suffice to say they didn't appeal. Of the other 2, 1 was a petite friendly blonde and the other a nice brunette with a decent figure. None of the girls were stunning, this is what you're paying for.
After a while, the girl will ask if you'd like to go to a room. She then walks to the front desk and asks for a numbered key. The guy on the door issues the key and makes a note in his little ledger. She'll come back to you and you follow her to a sequence of corridors at the back of the bar, these are all rooms with red lighting and a double bed. You get about 20/30 mins in there until the girl will suggest you finish so you can both go back.
I went with the little blonde first. We'd spent at least 20 minutes chatting prior to going to the room, this made possible by the sheer lack of numbers in there. After returning to the bar for another soft drink I then went with the brunette.
Oral was with condoms. I asked to finish over the blondes little breasts and she said no, but was very nice about it and said "ask one of the other girls, they might do it".
I would guess it was around 7pm on a weekday when I was there. there might have been 3 or 4 other men there, at the most. It was a very subdued experience. The website above has all the details (Preise = Price, which is stated as 99 euros). It would be interesting to see how the place is around midnight, and whether you are having to wait for the girls.