HK guys have been doing it regularly in Shenzhen and Dongguan for years already.
Two HK guys were my students in Shenzhen during my first year in China.

They both regularly dated and paid mainland girls for sex, one was even stupid enough to have unprotected sex with prostitutes.

Dongguan apparently has the biggest brothel in Asia, not been to inspect though.

Had mates that suggested going to Dongguan for brothel touring weekends, but it didn't really appeal to me. I know that if you was in Amsterdam, Soho in London, Las Vegas (or is just the rest of Nevada?) or anywhere in Germany/Austria, you would be tempted to try getting a classy whore because it is out there and legit/tolerated, but Dongguan... I know that guys who come for the Canton Fair often stay in Changping in Dongguan rather than Guangzhou, but it all just sounds like a larger version of any back street in China.

Not to mention that most of the girls come from the skankiest disease ridden places in Hunan, Henan, some are desperate for cash or abducted etc. I'm not really a hooker banging person but if I was to get one, I'd prefer my whores to be a little more free-range, if you get what I'm saying? I don't want to feel like I am practically raping somebody and then also paying for the privilege at the same time. There has just got to be a fair amount of human trafficking or migration out of desperation to Changping and I don't feel comfortable with the idea of supporting it with my patronage.

However, although I say that I'm not a fan of hookers, I must admit that I would love to go to one of those 'soapland' places that you see on pornos in Japan. I know that you've got to pay for it, but do you honestly believe that you could easily persuade your girlfriend to mess around with inflating the air-bed, buying the nuru gel, getting 38GG breast implants etc? I already have a tricky time trying to persuade a girl that I'm currently dating to try simpler things, lol.

Extreme caution should always be used. You might avoid Aids but you can get other nasty stuff like the clap. I knew one French man who contracted syphilis in China. SOme cities in China now have a 72 hours visa that are given without medical checks, or even just a plain tourist visa that people use to go partake of the locals.
I hear you about those bar flies. Sometimes you just have to say no and go home alone. This goes with what I tell new teachers: "Say no more than you say yes."

There will even be god knows what disease ridden men flying into BJ or SH for whore-banging weekends/stopovers en-route to other places. HK guys have been doing it regularly in Shenzhen and Dongguan for years already.

For Russians and Koreans especially, they are going to have loads of cheaper whores right on their doorstep. I even think that some of the Japs in Dalian, do enjoy making use of those 15 day visa-free stays, lol.

I suppose the chance of an individual laowai contracting HIV in China is relatively remote, but people still do get HIV. I think the chance of any individual being killed in a plane crash is 10000 to 1, remote, but jets still crash. Contracting HIV is probably more like 5000 or 6000 to 1. Anyway, it's all the other stuff I'm more worried about, and the chance of getting something is pretty high.
I've had unprotected sex in Asia many times, not saying it's right, I think I was very stupid to do that. Now I would always use condoms with hookers, and I think for one night stands in China a condom should be used also.

I would argue that the disco slags are actually far more dangerous than the hookers, hookers will often insist upon protection as their sexual health is their livelihood and they need to protect it. As for one-night stands... In most cases, you do not really know who it is that you are sleeping with.

As for me, I've always been one to use protection, except with quite serious girlfriends where the heat of the moment has made it hard to stop and get one out of the drawer. But as I have said, condoms do break more often than you'd think. Although A.I.D.S is rare, galloping knob rot is very common and I don't want to get that.