The woo-ey aspects are actually pretty interesting. Since the mechanism relies on focusing your subconscious, belief is crucial. If you don’t believe in your goal, and the efficacy of the method, your subconscious won’t buy-in, and without subconscious buy-in it flat out doesn’t work. Subconscious buy-in is the mechanism. You can’t try to consciously trick the subconscious, it’s in there with the one trying to trick it. You have to really believe.
A lot of people can’t believe that it’s internal. They don’t think that ability could possibly be in them anywhere, so in order to cultivate the requisite belief they have to attribute the mechanism to some kind of external woo. So even if the woo isn’t real, belief in the woo can be integral to the mechanism working.