Actually dear Gib, there were all sorts of cults on the go, and a history going back over the centuries of people's own private takes on the world. The hey-day was probably at the turn of the 20th century, but quacks and frauds have been around for many, many years. The thing is, I suppose, is that at the time Old Bro Hubbard was smashing his way into history, there weren't many that promised so much for so little, and delivered even less.
As for the science involved? nope, just a bunch of smoke and mirrors, and Hubbard, the lazy bastard he was, pillaged the unknown and sold to the gullible, the effects of which we see here. He was mucking with the mind without a map, and I am sure at some point he figured it was harmless, but the monster he created, the cult was, and is, far from benign.
My wee thought of the evening, and bugger the short edit times here at ESMB because this is the sort of post I loves to add to, but oh well
I realize what you write. In fact I have an old 1912 " Modern Electonics" magazine I am looking at right now, and the back pages have advertising for get this, the headline of the ad: The World's Greatestest Hypnotist Writes A Book, by Herbert L. Flint, Known to the World as the Father of Modern Hypnotism, is the Author"
If I knew how to post a picture of it here on this post I would, but I don't know how to do it.