The use of concepts that are impossible to measure enables success to be claimed even though nothing has actually been accomplished. Don't fall for paranoid accusations. Unconventional practitioners often claim that the medical profession, drug companies, and the government are conspiring to suppress whatever method they espouse. No evidence to support such a theory has ever been demonstrated. It also flies in the face of logic to believe that large numbers of people would oppose the development of treatment methods that might someday help themselves or their loved ones.
True scientists share their knowledge as part of the process of scientific development.
Quacks may keep their methods secret to prevent others from demonstrating that they don't work. No one who actually discovered a cure would have reason to keep it secret. Be wary of herbal remedies. Herbs are promoted primarily through literature based on hearsay, folklore and tradition. As medical science developed, it became apparent that most herbs did not deserve good reputations, and most that did were replaced by synthetic compounds that are more effective.