1. Acetone soak. Place forend in a small tub, submerge it in acetone, leave it for a few days, a week, etc.
2. Whiting powder
3. Citri strip. Boil water with a few drops of dawn dish soap, place forend in water for around 5 minutes. Pull it out. Let it air dry for around 10 days to two weeks. If there’s still excess oil, use whiting powder or soak in acetone. This method is ideal if your planning on refinishing the forend. It automatically whiskers, raises dents, pulls dirt and oil from the wood, etc.
