What I read on some Chinese sites (Shanghai night life specifically) is that if it is your room ( only applicable if you are in areal legit hotel), it is almost impossible for the police to prove that the girl is an escort, unless you or the girl give yourself up.
If you stick to a story of "she's my girlfriend", "I met her at the bar and we are having a great night" etc, there is little they can do.
I tend to ask girls to come dressed conservatively or casual, as to not trigger attention.
I am not sure the police can forcefully gain access to the room either. In any case if someone knocks at the door whilst your in the middle of it, get you cloth on, keep your condom on under your underwear and act as if she really was your girlfriend or night conquest.
Then pray for the best!