The lady on 'It's Me or the Dog' doesn't use a choker, on a large strong dog she does use a harness rather than a collar. The only thing I have seen her do is stop a dog from pulling and taking their owner for a walk rather than the other way around. As long as the dog isn't pulling she is praising them, when they start pulling she uses a sharp sound with her voice to get their attention and then starts walking in the opposite direction. Eventually they get the idea that if they want to actually walk somewhere rather than in effect walking in circles they have to stop pulling. She does a lot of distracting, focusing, and treating. She often uses a clicker followed by a treat.