When you find vintage plates and other tableware at thrift stores or flea markets, there’s a simple step you can take to disinfect them and remove tough stains. The secret ingredient is hydrogen peroxide. But rather than drugstore peroxide that’s 3 percent strength, ask the pharmacist for -- 20 percent hydrogen peroxide for your plates. The stronger solution will remove stubborn stains and act like a bleaching agent, all without harsh chemicals. Just pour the hydrogen peroxide onto your plates, bowls or cups and wait a few minutes, then rinse and dry.