Prong collars are not sharp though. The cheap ones at pet stores, yes, but proper brand ones like Herm Sprenger are rounded. They don’t hurt if they are high quality and fitted right. I’ve used them on my own neck and I have chronic pain. Uncomfortable, at most, but not painful.

Did you not read the post I commented on? The one explaining the physics of the whole thing? 

You are placing around the neck of a strong animal a collar with inward-pointing prongs. You then proceed to apply pressure to the collar every time the animal doesn’t do what you want, with the sole purpose of causing discomfort and possibly pain until the animal obeys you. 

Unless you tied the collar to a leash and put your full weight against it with nothing but your neck, you don’t know what the collar actually feels like. 

Yanking on a regular collar that distributes the force is bad enough without getting prongs involved.