Although the name "Whink" is now associated with several cleaning agents, the name is usually connected with a hydrofluic acid-based solution used for removing rust stains. The Whink website states: "products containing hydrofluoric acid, such as Whink, not only etch glass but cause severe burns to the skin..... Whink is extremely hazardous. WEAR RUBBER GLOVES. Do not get any on your skin! ....... Extract after use."
I do not think we want a caustic solution going into the DCHS drainage.