Yes — Sounds like a fret polish is needed. One way to do this which is inexpensive but can be a little messy is to use 0000 steel wool which is safe to be used on a rosewood fingerboard if you go with the grain, but always use a steel fret mask or masking tape on a lacquered maple board. If you do use steel wool, also mask off the pickups as the magnets can attract the little bits of steel wool that break off