If you're wondering if it really works, yes, it does. One of the key elements of it, especially when using it on people, is accepting that the subject is likely to execute the behavior badly for the first few iterations, but you have to positively reinforce it just the same as if they'd done it perfectly if you want them to get better. If you can't manage this, and you get angry at them, you're jeopardising the whole thing.
There's a nice clip from one of Jordan Peterson's lectures here, talking about these techniques in the context of intimate relationships: