In my experience the Romanians who work in German FKKs are significantly more engaged than the ones you meet over here - probably because a dodgy pimp isn't taking half their earnings.
I have seen plenty of evidence of pimps in the FKK.
Guys in towels (so not FKK employees) openly instructing girls
I remember watching one guy sat down and a succession of girls all came up to him for an intense conversation, some left happy some left in tears
On a trip to samyar this have this sort of circular dance thing and this guy was pissed off with his girls for not dancing, he was straight over and they looked scared.
It happens, but what percentage are pimped Ive no idea. if you meet a girl in a club and go to the room with her and she seems happy enough how would you ?
but I think the %age of pimped girls is lower in UK prostitution than it is the FKK