Neck cleaning four-step
I just got my Strat back from my tech, installing an Earvana compensating tuning nut (
www.earvana.com, you gotta see this, man, it's sweet). I asked him about how he made my guitars' necks look and feel so good. He gave me a four-step process for bare wood fretboard (i.e., like a rosewood fretboard, as opposed to a shellaced maple fretboard):
Clean. Use a pretty dilute solution of water, dish soap and ammonia. Clean with cloth and if you need to remove gunk, use soft tools like a credit card and a toothbrush. Wash, wipe off, let dry. (Let it dry, let it dry, let it dry! Don't advance to next step if it's at all still wet!)
Oil. Wipe on a little lemon oil, rub it in, let it soak in, then wipe off.
Sweeten, seal, make it look beautiful. He then uses some Minwax brand Finishing Paste, rub on with a clean cloth, hand buff, dry, hand buff.
Then machine buff it with a . . . a buffing machine. This last step is pretty much optional, who's got one? (You can buy a little buffing attachment for your electric drill, though.)
It's several steps, and this is pretty much the therapeutic course for a dirty, somewhat neglected fretboard. If you do this, you can subsequently just touch it up with the lemon oil step, and then maybe every year or two do the whole treatment.