Have you noticed that a maple fingerboard with a satin finish tends to get discolored over time due to finger sweat and grime? I would really like my maple neck to maintain its light wood color and not be subject to the dark discoloration due to normal playing. What do you recommend for cleaning it (getting the dark discoloration out)? A friend recommended rubbing alcohol. He said it gets the grime out, and leaves the wood with its original light color. I would think that this would remove the satin finish and wood sealant. Comments?