Winnietrey, I'd suggest that now that you have made an impression on the dog, that you try the non-aversive techniques without the prong collar.
I have heard from a lot of owners that their dog improved instantly with the prong collar, but that with continued use the dog began showing a strong dislike (not wanting to go out for walks, not wanting the collar put on, etc).
Of those, the ones who then eliminated the prong collar and started using the non-aversive methods, saw the dog respond better to those methods (even if they didn't respond to them before using the prong collar).
For me, I've never had a dog who didn't respond to force free training.