This guy worked in corrections for a long time, and regularly had to extract prisoners from their cells that did not want to come out. He could usually talk them out be using these techniques. The whole point of it is to recognize it, understand the dynamics, avoid it, reduce the threat, or escape from it. The techniques are very practical and not difficult to learn.

He does carry it way beyond and teaches the actual violent techniques as well. But you can't learn that from a book, or in a forum.