In North America, Vanish is a brand of toilet bowl cleaner manufactured by S.C. Johnson. They obtained the brand through the purchase of The Drackett Company in 1992.
Drackett purchased the product from inventor Judson Dunaway of Dover, New Hampshire, who introduced Vanish in 1937 as a competitor to Sani-Flush, a toilet bowl cleaner made since 1911. The products were substantially the same. The active ingredient in crystal bowl cleaners is sodium bisulfate (also known as sodium hydrogen sulfate). Surfactants are added. This forms sulphuric acid when mixed with water. The last Sani-Flush patent had expired in 1932.
Most other household cleaners are basic (alkaline) in nature.