Click on Advanced Search in the upper right corner and then type in womach and search. You'll find 2 threads with negative reviews of the Womachs' "flooding" technique. Not healthy for birds or humans.
Womach started out using a "flooding" technique that makes the animal go into "learned helplessness" but their new videos are actually going into positive reinforcement. Does that make their newer videos any better? I can't say, as some may argue that his videos do not show the time commitment involved to properly train a parrot.