I haven't used a prong collar because they look so awful, but after reading this, I think I might try one on Speedo(Cloud-Prince)-- he pulls horribly, and i don't think a choke collar (like I used to train Star) is going to deter him much. I used a Gentle Leader head collar with my Rosie, which worked like a charm, but Speedo has so far successfully thwarted my every attempt to put one on him.