I've got a 1993, 94 year Rem 700 with wood stock and I've never actually cleaned the wood. It's been kept in a safe most of it's life. My only thing is wipe it down with a clean dry clothe so that no cleaning oil, dirt or other chemicals are on it before I put it back up. Doing this has given me no problems, still looks great.
If there is a proper cleaning technique, I apparently missed that memo..