There was an incall I visited that had an interesting test to protect themslves, and interestingly it protects the client as well. 2 call system and a warning to not discuss money at all when you arrive, to have the $$ in an enevelope and to follow instructions. They let you in the door, and the first thing the Madam does is tell you to open up your fly and pull out your dick. She then gives it a little tug, gets down on her knees and places a rubber on it that she has been holding in her mouth. You are told to not remove the rubber and to leave your dick out as you are escorted into a room, where the ladies parade through for your selection. Once you have chosen the Madam comes back and asks if you have an envelope for her, takes the $$ and then sends in the girl. Nobody in LE is going to play with your cock (protecting you) and no cop is going to pull out his dick (protecting them). It also was a kinky warmup.