The problem isn’t the sex-workers, it’s their clients? Really?
THEN
A girl in my former block … had all sort of clients coming through or waiting in the foyer at all sort of hours, often times with their mates awaiting in the car. And your property becomes known as such to all the wrong sort of people.
It sounds like you are agreeing with me (in a backhanded way). It’s true that without the sex worker there would be no clients, but without the clients there would be no sex worker. Deter the customers and the lady of the night will move on – try to deter the working girl and you face all sorts of legal rights issues.