What amazes me here is how prevalent these advertising claims are even today. I wonder if these claims really originated from advertisers or if the advertisers

What amazes me here is how prevalent these advertising claims are even today. I wonder if these claims really originated from advertisers or if the advertisers themselves have a basis elsewhere (maybe folk medicine, or something they observed Native Americans did, etc.) and just gave it an audience. Hydrotherapy sounds like the contemporary endorsement for cold showers (even if, I think, some of the claimed benefits of cold showers have been proven). > “quicken the blood supply, increase the scalp’s nutrition, and thus aid nature in keeping your hair alive and beautiful.” > Stimulating massage plus lather plus water flushes out “dead cells” and “dust,” leaving “the pores clear and free to do their work.” Are natural hair care advice you can get even today. I have completely no idea how these have fared against scientific testing. All I know is that there is still a lot we don't understand about hair care and so you are bound to get a lot of conflicting advice. Heck there isn't even a consensus how frequently should you shampoo your hair. > Only the fresh-squeezed juice of a lemon, Sunkist offers helpfully, “cuts the alkali in the soap and leaves the hair really clean.” I distinctly remember hearing this sort of advice in my school's grapevine just around the time we were going through adolescence[1] and just getting conscious about how we look. Even with the hormone-clouded judgement of an adolescent, I could tell this claim has disputable basis; citrus is acidic and why the hell would I want anything acidic on my scalp? What really gets me is I am not from the US. Granted, we were a colony and not to mention US is influential even to non-colonies. But I find it very amusing and curious that I heard such a singular and obscure advice, which Sunkist apparently promoted almost a century before. I wonder, if I could trace back how this idea propagated to me as a pimply schoolboy, will it have originated to Sunkist's ad? Or perhaps share a common ancestor with it? Man, ideas are damn hard to kill. [1] If I really try to place this memory, I would say around 2004.