Practical life-penny polishing WARNING!!!!!

I have seen several penny polishing ideas on blogs showing people using vinegar to have kids polish pennies. Vinegar and copper makes chemically  a DEADLY POISON! My mother would put three or four pennies in a  jar with vinegar to make this. It was her home remedy for ring worm. It is absorable through the skin. This means using that seemingly harmless vinegar everyone is going green and cleaning with to clean pennies could POISON YOUR CHILD even if they never put anything in their mouth!!!!!! Please use caution do not do this. My mom always said it was a deadly poison. No I don't recomend putting it on ring worm either thank you.