Has any technique or treatment formerly labeled as "woo" been later determined to be valid?

Not medicine, and so not strictly relevant to this thread, but still:

“Continental Drift” (Wegener, 1912, and earlier theorists) sounded pretty crazy until scientists came up with a few more observations and theoretical underpinnings. It’s now “Plate Tectonics” and is now standard Geology.

Check out the documentary “Gizmo”. A tribute to the kitchen table inventor and the backyard mechanic. People who realized their dream - not always successfully.

I was just discussing cupping with one of my son-of-son-of-Jews from the old country, whose father, like mine, received hot cups sucked on to their skin, when removed leaving a nice circle but taking away bad stuff.

“Bahnkes” I think it is called, in Yiddish.

Anyone use that?