My weird Catholic-convert dad had a faith healer who ripped him off by selling him bogus blood tests. His credentials included, I shit you not, teaching at a "holistic dental college" and writing long texts about how being a Catholic nerd would cure you.
When COVID came this quack told my dad not to worry, since he could cure it easily. Luckily he died, and my dad began seeing real doctors again before that would become relevant.
I know you shouldn't be a snitch but I reported the quack to the authorities for impersonating a doctor. I never got any response and I don't know if they did anything before he died though.
Yes, if it wasn't clear that I was joking, fake medicine and fake doctors are extremely dangerous and should be extremely restricted and heavily policed in any functional society.