[crisp]

The collar you are using sounds like a nylon slip collar. The collar already administers a choke to your dog so, as Stosh said, I would recommend the prong. It does less damage long term to your dog, and as a poster mentioned above, it is like power steering. Also, a few corrections from a prong is better than 100 from a slip collar. Its not too hard to use. Leerburg.com has a good article on fitting a prong on your dog. Just type in 'prong' on the sites search option. Your trainer can probably show you also.