If you are able to walk around the city, assuming you can, just go to a university in Prague where girls are really liberal about having an one night stand with a stranger for a bit of cash. Unlike pros, these girls don't have know a freaking clue how to negotiate. You can find stunning innocent virgins.
Most of the girls come from the countryside of Czech. I know that there's a chance of these girls being prostituted when they were teens, but what?
I'm sick of pros, man =) I want some innocent girls.