The things that work should get more attention from the mainstream psychologists IMO. (It's been nearly fifty years since we have had a cure for phobias. At some point it stops being funny and starts being tragic. Everyone today who has a phobia is suffering needlessly.)
As for the "theory that someone just made up." That sounds weird to me, because my experience has been that theory is treated as no more than a prop to support hypnosis. The emphasis is always on the pragmatic and empirical. If you go read the books like "TRANCE-Formations" they are really upfront that they have no idea why this stuff works.
Whatever NLP is, they collected "a bunch of things that do work" many of which no one ever noticed and wrote down before, eh?
> CBT and exposure therapy, is this what you're referring to?
No, this is something totally different.
The core of the process is a double-disassociation and a kind of time
reversal. You watch yourself watching yourself watching yourself and
then play the movie backwards. Somehow that changes, quickly and durably,
the way the brain responds (to kittens or elevators or whatever.)
(Even the stuff that made it to education science doesn't work. There's no such thing as a "visual learner".)