Depends on the country or city. I've heard stories that in the past, Korean guys who do their mandatory military service would all get taken brothels and everybody had to bang a whore or you'd be shunned and shamed, which is a big deal in a group conformity oriented culture like Korea. And anybody working in a large company, whether executives or factory workers, would go to outings that involve girls that would suck you off at a minimum.
I've asked female Korean friends in Korea if this was true and they didn't disagree, just didn't want to think about it. I asked if that meant all their male friends, brothers, fathers, colleagues, men they're dating, guys they flirt with at parties, every man they knew was banging prostitutes and they just didn't want to think about it. But no objections to the conclusion...clear signs of cognitive dissonance. If I had to guess, 70%+ of Korean men have had at least one experience with a prostitute...maybe 80%+.
When I spent a lot of time in China, HK, and Taiwan, there were brothels on practically every street corner of even medium sized cities. First time I was in Taipei, I saw KTV signs more than any other sign and was amazed there were so many TV stations, which in hindsight was a comically clueless and naive conclusion.