Here's an easy home cleaning solution for your jewelry.  

1 tablespoon salt
1 tablespoon baking soda
1 tablespoon dish detergent
1 cup water
1 piece aluminum foil

Directions:

1. Heat water in the microwave for 1 or 2 minutes.
2. Cut a piece of aluminum foil that roughly covers the bottom of a small bowl (like a cereal bowl).
3. Pour hot water into bowl. Place salt, soda and dishwashing liquid into bowl. Place jewelry on top of foil and let it sit for 5 to 10 minutes.
4. Rinse jewelry in cool water, and dry jewelry completely with soft cloth. Discard solution after use and make a new batch next time.

According to wire-sculpture.com, "This works well for gold-filled, brass, german (nickel) silver and sterling silver."