Eromedicine

Josh spent a lot of his life in hospitals. In fact, he was in a hospital right now, playing with his phone. And he was a huge pervert.

After verifying that the app works, the first thought that came to his mind was "make hospitals sexy". Both for the direct benefit, and because he loved the idea of perverting an institution that was so professional, and so dedicated to care about people.

The problem is that, as Josh knew from spending so much time in hospitals, adding sex to them doesn’t lead to a good outcome. Illness is unpleasant, and not sexy. Even getting sucked off by hot nurses wouldn’t actually be enjoyable when you are feverish and nauseated (which Josh wasn’t at the moment, fortunately, but he wasn’t very far from it). Without solving that problem, he shouldn't make his main change.
He could make it so illness never existed in humans at all. But that is a big change, one that would leave civilization totally unrecognizable. And all changes made by the app are retroactive. He would also like his perversion of institutions to have a baseline people could compare to, so they would notice that perversion (but could do nothing to stop it).
And, in addition to all that, as a bonus he would like to sexually dominate women, to ensure all women are sexually dominated, and for reasons that are objective and no one can argue with.

Can he kill 4 birds with the same stone?
He can.

• Large concentrations of fluoride are never harmful to the human body.
• Large concentrations of fluoride in a human body react to activity the human considers sexual, in what Is known as the Eromedical Effect. The Eromedical effect creates a large amount of hormones, neurotransmitters, and blood cells, causing fast healing of all damage in the body, faster and more effective than any possible medicine. The rougher and harder the sexual activity, the stronger the effect. The exact manifestation of the effect depends on the specific sexual activity, and different manifestations are best suited to treat different problems. For the effect to occur women need to be the object of sexual activity, and men the subjects, but otherwise the manifestations are symmetrical. The exact pattern of manifestations is complicated and requires medical study to predict.

So sex heals you, as well as any activity you consider sexual that isn’t exactly sex (such as, for example, spanking). All sex heals you, but some acts are better for headache, or broken bones, or anything else, than other acts. You need a doctor to prescribe what kind of sex you need to have for any specific ailment. Women have the same healing effect from giving blowjobs as men do from receiving blowjobs, or being fucked in the ass as men do from fucking a woman in the ass, but both have the same effects from lip kissing.

• The Eromedical Effect can only be first discovered through scientific advances of the 20th century, and only in populations that consumed fluoridated water for more than 3 years.
• Medical systems aware of the Eromedical Effect replace all methods they can with Eromedicine, as it is clearly more efficient than all other alternatives.
• Prostitution in countries aware of the Eromedical Effect is legal, but regulated as a form of medical treatment.
• Old style white dress nurse uniforms are never replaced with scrubs, the only change that can happen to them is the hem becoming shorter, and cleavage deeper.

He considered adding a rule making it socially unacceptable for a woman to refuse sex with a friend or family member for Eromedical purposes, but decided that social norms would change themselves, without need for magically enforced rules, when physical health is at stake.