WHINK RUST STAIN REMOVER – Rust Stain Remover in the “brown bottle”, has been the #1 pure liquid rust stain remover since 1947! This convenient liquid formula quickly and easily removes rust stains from white sinks, white toilet bowls, gelcoat, as well as colorfast fabrics & carpets. No Scrubbing Required. Product is sold by the 10 oz. and 16 oz. bottle.