Amazondoc, you have recieved some good advice and your on the right track with contacting the gun club for instruction, while there you may make some good friends who are more than willing to care for any predators you have.
As for my thoughts on a firearm for you it would be a single shot 12 Ga. shot gun.
Heres why,, to start they are simple to use and care for,
and much easier to make a fast kill shot than with a .22,,
with O buckshot you will have a very lethal cloud of twenty .30 caliber pellets.
I would NEVER use rock salt, it will break skin possibly leading to infection and anyways you made it bleed. If your gonna shoot it, kill it, you don't want a wounded animal running around
There are commercially loaded NON-LETHAL rounds for a 12 Ga. such as rubber shot or bullets and caspium pepper, a much better choice if your intent is detering two legged varmits