The problem though is like Krystal said earlier. And I agree with what she said very much, and a couple others as well.
We know it happens. Most of us have done it with someone outside marriage (one night stands, fwb's, providers....). Most of us have at least once.
The thing is that *advertising* just pushes a stygma that is already bad enough as it is without extra help :/
I won't judge someone who does advertise but I also think advertising is not the smartest thing to do. If the chemistry between two people is perfect, everything is super passionate, and you both feel safe in it, or you have come to know each other, etc etc or whatever makes you feel safe, then people engage in it "sometimes".
Advertising it just becomes an invitation to all sorts of weirdos, and definitely increases the rate of STD by "some", even if it didn't by much the stygma would be horrible. And that's even IF every sex worker took a type of PreP it would still go up some; maybe they don't take it as prescribed, can't get it once or twice, or that random one insane chance through higher occurrence rates, etc...
To make matters worse, not even close to half the sex workers are taking PreP. I'd be willing to bet less than 30% are even aware of its insane efficacy. Even then though, even then, it's still not an invitation to just advertise it. Nope. Definitely not