Bar Keepers Friend can be used on: Clean work surfaces and remove stains caused by tea, coffee, juices, markers etc. Ceramic and stainless steel basins to remove dirt, stains, soap residue and limescale deposits. To remove tea and coffee stains from porcelain and glass. Cooktop to clean ceramic hobs and glass oven doors. Remove burnt-on food and rust from cookware. Chrome, plastic, Formica, tiles, joints, copper and brass; Instructions: sprinkle Bar Keepers Friend on a wet cloth or sponge, rub gently & wash. For more stubborn stains, add a few drops of water to the paste, remove after 1 minute and rinse well. For brushed metal surfaces, rub in the direction of the brushes. ‘The secret of BKF’s cleaning power is oxalic acid. Discovered by a chemist by Chance in 1882, who noted that his pot cleaner after cooking rhubarb, the original formula was still superior to many modern cleaners.