hello all! im having some trouble when im finish sanding a handle with a light colored wood. when i do the area near where the blade is snadwiched between the the 2 handle scales i end up with a dirty area.after its done i scrub it with soappy water but i cant seem to get it all off. i know most of the dirt must be metal "powder" but i think mabey some might be from the sand paper. what are some ways i might get it a bit cleaner? thanks so much!willy