[a fool in paradise]

I'd forgotten about that

[frank ballenger]

Not as vitally important as your topic example but it was promoted and believed by John W. Campbell, the first editor of Astounding Science Fiction (later Analog) that Listerine mouthwash killed off dandruff and stopped its return.

And the multimillion copy bestseller Think and Grow Rich author Napoleon Hill believed that the reason for male baldness was wearing hats with tight rims. He wrote that stopping that practice would end all baldness.

[Kickass Conservative]

And it makes a nice Mouthwash too...