My new-to-me first gen. (1968) BAR is deserving of all the loving care I can give it. During my initial dismantle for cleaning and inspection I have found the walnut fore end to have an appreciable coating of soot on it's interior. I want to apply a sealant to the raw wood, but the cleaning aspect (without imparting damage of some sort) is a stop-gap/mystery to my going forward. Is there a non-moisture cleaning agent that will help with my dilemma, or a solvent that will evaporate readily enough so as not to be absorbed into the 50 year old exposed woodgrain?