I've had good luck in the past with an oil used on wooden clarinets.You can get it at any music store that stocks traditional wind instruments.It's cheap and easy to apply.I just run a small bead up the fingerboard,rub in with an old soft cloth and let it soak a bit before wiping it off with a clean towl.Don't use to much as you wouldn't want it to gunk up under the frets.It looks great.
