I also like the gentle leader and use
it with Rocky when we are walking
in public places, (because he is dog aggressive. )
The gentle leader calms him down.
Sheba who use to pull, never took to the gentle leader.

The first few minutes of our walk, Rocky will try
to paw it off. When he does this, I stop walking,
keep his leash tight enough so his head can not
reach the ground so he doesn't hurt his nose. Than I put him
in a sit stay. After a few times of him realizing we
are not walking unless he stops fighting the Gentle leader.
he starts to walk very nicely. I use a choke chain as a back up collar and hook the leash to both the gentle leader and
the choke collar.
That way if Rocky was to break the GL the choke
collar would than control him.

I have never tried a prong collar, but
I bet that would work too.
Either one you use, make sure you use it properly.