Chlorine and Chloride will react with the surface of your stainless steel appliances, appliances, bathtubs, and sinks, turning them dark. In addition, these chemicals will cause water droplets to form on stainless steel surfaces when it's cold outside, creating rings and stains on the metal. Vinegar is really effective at removing these chlorine stains on stainless steel because it neutralizes the chemicals. You can also remove stains on stainless steel with lemon juice or hydrogen peroxide, both of which are great cleaning agents.