Last I checked colloidal silver was being sold by a christian evangelist named Jim Bakker. Then there's chiropractors. Then there was the anti-vaxxers. Then the "vitamins will cure anything under the sun." Then there was things like "all-herbal fen phen" and other herbal products. Then there's that famous goop company led by a has been actress which has some questionable products, but sold to housewives. Oh and the entire premise of homeopathic medicine is a fraud.

And then FDA approved drugs like fen phen (Wyeth) which should not have made it to market some how did, and caused heart valve problems.

Hell, when you think about it, what the fuck exactly is holy water which is used by the Catholic church?

If you can dupe people into the premise that "Magical Things are Real", then it becomes easy to take their money away from them. And right now, it doesn't seem too hard to do these days.