I send this to my families when they have questions about prong collars,
I also have them have a trainer show them how to use a prong collar properly. The prong collar is essentially 'self correcting' if used correctly, and the leash correction, or "pop" is relative, some dogs need very little pressure, others might need a small "pop". A prong collar is a training tool, and should never, ever be left on the dog after a training session.
I also second the fisted treat technique. Sit with him and practice feeding him his dinner one kibble at a time, and only give him a kibble when he is polite about it. You can add a conditioning word while you do this, such as 'easy', or 'gentle', that way he will know what you want when you ask him to take the treat correctly, and use the conditioning word, in other situations. If you work first on
just taking the treat nicely, until he gets that down, he won't get confused later when you are trying to reward him for good behavior, but get mad at him because he bites you. That sends confusing messages and he will get frustrated.
Leerburg Dog Training | How to Fit a Prong Collar
My best to you, good luck!