You won't believe this but being a smoker, I had to come up with something to clean the walls in my smoking room, before she, would allow me to smoke in there so found Selley's Rapid Mould Killer, gets rid of the stain, the smell, and everything else, just leave it on for 30 seconds then wipe it with a damp cloth, then clean cloth washing it with water , then wipe dry. Make sure you open all windows, , and you wear gloves. It works. Or you can use liquid sugar soap, but that is harder work to scrub it all off.