WHINK 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 as well as colorfast fabrics & carpets. No Scrubbing Required! Not A General Purpose Rust Remover. Read Precautions And Directions Before Using. This Is An Acid-Based Product.