If it's any consolation, Larry, I've also heard about using cornstarch on cuts but have no idea where I picked it up. More often I've heard about rubbing Comet cleaner (or similar products) or lime on a cut. I think the lime is supposed to make it callus quickly to prevent an entry point for rot. Comet, obviously, has bleach in it which would kill the bacteria if it contacts it. Air drying probably helps with the callus depending on the plant.
