Clean tarnished silver Another fun trick: All you need to clean tarnished silver is toothpaste with baking soda and an old rag. Just rub it on with your fingers and wipe it off. It takes all of the tarnish off immediately, is so easy, and is completely non-toxic. In Montessori our children polish silver for prewriting skills and they love it. For copper tarnish, use ketchup.