Hotel security can take a lesson from casino security dealing with prostitutes:

1) Keep tab of who's who. If the hotel security does its homework, sooner or later you can tell who are the "regulars" here and you are pretty sure they are who they are, this way you don't upset the real female guests that dress like them. As this article hinted, prostitutes have their own turfs and usually after a month of data collecting the security can probably identify 90% of working girls that frequents your establishment for a score.

2) Once you've identified them, keep them moving or if they hang out at a bar they have to BUY drinks. This is a way to restrain their inconvenience real guests. If they are at the lobby they can't sit and do nothing but they have to move either to a bar, restaurant, to buy food and drinks, or get out. This way you keep the lobby clean. At the bar/restaurant bar, they have to buy drinks if they wanted to stay.

Really not that hard to police, casino security made it an art of win-win situation: guests are not bothered, prostitutes knows the rules, and the real johns are happy too.