In the 1920's, Harry Hoxsey came up with an unorthodox cancer therapy, composed of wild plants and home remedies.
I'd never heard of this guy, but he has quite a following, even today [well, he's dead (from cancer, natch) but you can still get his therapy at his clinic in Tijuana]. Although the Wikipedia page is pretty skeptical, Googling produces a lot of hits from believer sites. The Amazon page is almost all glowing reviews, and the lone 1-star reviewer gets piled on by 6 comments accusing him of being a shill for the great medical conspiracy. Most of the Netflix reviews are 5 stars, with huge upvotes, and one 1-star review that 1 of 3 found helpful.
And sadly, it looks like a pretty complete scam. "In 1956, the FDA sent an investigator to Hoxsey's clinic posing as a patient. The investigator was told by Hoxsey's clinic that he had cancer (he did not), and that it would take a "long time" to cure him." It's just about the same story as the psychics who will cure you from that curse that's on you; all you have to do is bury a huge pile of cash. Except, of course, that some of these people really do have cancer, and forgoing standard medical treatment can be detrimental.
Yes, yes, I'm a shill for the AMA.