I realize this was probably dangerous, especially as someone who doesn't know what he's doing. I did this in the open air with a particle mask and I kept my distance, added things slowly.
But I want to know a little bit of the science about what happened to my pennies. I had a hand full of pennies, many were nasty, there were a couple newish ones. As per internet advice, I put them in a solution of salt and apple-vinegar, because I didn't have regular vinegar, in an effort to clean them and it worked real well on some. It was so fast I was a little excited about it, so I took it out side and added bleach. Most of them developed this coat of dark red, which I could scrub off with a wire brush. Also, the salt and vinegar, which looked like really dark urine, turned bright blue green when I added the bleach.