i posted a note for help to clean a couple old barber strops with canvas backing. one reply recommended i try steam. i have a hand held steamer and used that on the old canvas. it was stained, moldy, looked awful.the steam worked quite nicely removing that (and im sure sanitizing it). then scrubbed the canvas with dishwashing soap and a brush. after, i used a hair dryer and then laid the canvas in the sun for a few hours. good as new! (well close). thanks for the tips guys!