People have been told before in the lounge of the hotel I spent 5 years at, this lounge is basically opened up into the lobby "this attire really isn't appropriate for the lounge", these were actually guests/patrons, not hookers, they just sure as shit looked like what someone who didn't really have any clue whatsoever would think a hooker looked like (basically they looked like tramps), other times it was "this behavior isn't really appropriate for our establishment" when people were acting out. The odd time they were guests they weren't asked to leave the premises, they were asked to change or retire to their rooms, simple patrons and not guests were asked to leave. A large percentage of the hotel staff was not permited to use the restaurants/lounge or bar in the hotel as they tended to dress down and act rather, boisterous - if we wanted to spend our own money in the hotel we had to have special permission. We knew there were escorts in our hotel, we didn't care, actual escorts weren't making scenes, weren't drawing any attention, and most certainly weren't causing problems. Simple fact of the matter was, we didn't care what you did behind your closed payed for room door so long as it stayed there, advertise, draw overmuch attention, create a scene in our public space were it affected other guests and then we have a problem. The majority of people (and I've said this before) that have had these rules applied to them, were not working girls, only once in 5 years were actual prostitutes turned away at the door, and they had walked in with the guest (known around town, didn't not dress intelligently).
And no we dont have a set in stone "dress code" but it comes out when undesirables were around, know what I mean, aka it's a handy excuse.
Listen you're not going to always get your way, if your behavior/dress attire is set a certain way you need to accept people are going to see you for that regardless of what you may or may not be. My friends and I spent many years as "ski bums" our personal style was not business or even business casual, we were 25year olds who wore sneakers (clean, suede/leather, generally new in really good condition, but sneakers none the less), loose fitting jeans/khakis and hoodies - they were always clean and in good condition, but that is our matter of dressing none the less. Being able to afford to eat/drink in certain establishments didn't matter, simply the way we dressed meant "nope, you dont fit in here", fine you move on - personally we weren't interested in spending time amongst people that fashion makes that much of a difference to.