When Jo was in obedience, they made us use the pinch colors. It seems like it would hurt the dog..but it never seemed to bother Jo much, and it worked amazingly. She listens so well with it, I was amazed! I use the gentle leader now though..I still have the pinch somewhere..My instructor told me that instead of strangling yourdog like a choker or even flat color, it just pinches the dog a little and is more effective or something..Seems logical :]