Whink Rust Stain Remover-351016, 32 oz: Attacks stubborn rust stains and quickly removes them from white sinks and toilets as well as colorfast fabrics and carpet. Liquid formula is safe on pipes and septic systems and works without the need for heavy scrubbing. Not intended as general use rust remover, use only on indicated surfaces. Powerful liquid formula is tough on rust while remaining safe for pipes and septic systems.