I sell vintage jewelry online auctions and occasionally run across pieces that have green gunky stuff called verdigris. Seems like it would be easy to clean off but isn't always, any ideas?
It works great for me whenever I did this problem and I had a lot of jewelry to clean after my mother passed away and I tried different cleaners too and there you have to be very careful not to damage the jewelry with cleaners. Vintage jewelry wasn't made to withstand harsh cleaners but toothpaste isn't as harsh as those cleaners are.
I've cleaned all my jewelry using toothpaste except for my pearls that is. Also, have you tried taking a very soft toothbrush and just using a good bar of hand soap and brush the heck out of the jewelry? This also works for most pieces of jewelry too.
Good luck cleaning up the verdigis on your vintage jewelry.