This is not true, and is dangerous to both the sex worker and her partner - neither of them can know if the other has had unprotected sex with someone else. Clients' wives and partners are also at great risk from catching AIDS or other sexually transmitted diseases. Usually they have no idea their partner is seeing sex workers, and have unprotected sex believing it to be completely safe. Sex work itself is not illegal, but soliciting is, and the police try to stop sex workers operating in residential areas. They harass workers and clients.
Life is difficult as the workers age.
There is an AIDS clinic in Hong Kong, but because of prejudice, and a lack of information and education, the neighbours object to it, and it has caused a serious localised social problem. The rest are controlled by pimps or work in Karaokes, night clubs, striptease shows, massage parlours, and saunas, and can be regarded as employed. People are more aware of their problems, and many people now regard them as workers in the service sector. But there is still a long way to go. Because the public in general only has superficial understanding about sex work, it is commonly held that sex workers get what they deserve when they are unjustly treated by the authorities or suffer violence from clients and police.