A company called Aguila makes a mini-slug. They are 1 3/4 shells that don't kick anywhere near as fierce as the big boys. They may be good for your practice range time. A 12 gauge shotgun will scare the crap out of most new shooters. This might give them that false sense of security they may need to pick it up. Just use them for practice though as they may not cycle well in your action. Only one way to find out.
Courage is just fear that has said it's prayers.
The people trying to say the 2nd Amendment is outdated are probably the same folks that would say the same thing about the Bible.