I'd guess most people have a friend who's always on a diet. When it comes to weight loss, dieters are willing to do crazy things and quack inventors are happy to oblige.
Neatorama has tabulated the 10 craziest diets in history and yes, at one point in time, some people did believe they could wash away the pounds. The pseudo science (emphasis on pseudo) is that certain seaweed soaps they can penetrate the skin and break down fat. Real scientists have found no evidence of the sort, just really clean test subjects.
Another genius claimed that the key to losing weight was to cut back on food (smart) and the way to cut back was to keep people sedated for days at a time (not so smart). This "Sleeping Beauty" diet would be more accurately named the coma diet. The dangers of this one are obvious. As are the dangers of the tapeworm diet.
The tapeworm is a vicious little creature that sits inside the stomach,
sapping nutrients from the body and growing to several feet in length, all
the while releasing millions of new tapeworms. It's gross and potentially
fatal, but it was also in a way the precursor to gastric-bypass surgery. You can eat the same foods and the tapeworm takes care of the excess. The
original tapeworms were sold by snake-oil salesman and, Neatorama notes, "it's uncertain whether these pills actually had live tapeworms." The Tapeworm Diet Web site promises the real thing.
Compared to tapeworms, the vision diet -- where you wear glasses that
make your food look unappetizing -- and the cotton ball diet of eating
(take a guess) cotton balls look tame.
Be careful about forwarding this list to your dieting friend.