WORKS WHERE ORDINARY CLEANSERS FAIL!™ For Use All Around the House! Removes Rust & Stains. In the Kitchen ZUD Heavy Duty Cleanser removes stains from porcelain sinks and stainless steel sinks. ZUD cleans countertops, ceramic cookware, and pots and pans. In the Bathrooms ZUD Heavy Duty Cleanser cleans and dissolves embedded rust and hard water stains in the toilet bowl. ZUD removes blue copper stains, mineral deposits and other discolorations in the bathtub and more!