NAKANO, I think it was Cougr Allen who said he used it to polish his leather shoes. Never tried it myself.
Would heating it up have any bad effects? Obviously, we're warned not to put our knives in fire, which ruins the heat treatment. Would this do the same thing? There must be some reason that this helps it penetrate better; perhaps it's a reason that's NOT so good for the knife long-term?
Howie