Luann,
Get some liver of sulfur that is in its natural hard state from a jewelry supply house. Just put a few pieces in a lidded plastic container and place your beads in the container it should oxidize your beads in a day or two.

You should put the liver of sulfur pieces is a small container so the beads do not make direct contact all that you need is the small amount of gasses that are released to do what you want.

Hope this helps you out.

All my best ....... Danny