I recently bought some stuff called "guitar honey" to try and clean the grim off of my Bubinga/Walnut Cirrus. The stuff says its for dark wood fingerboards, so I tried it on my bass itself since it is dark wood. I must say I was very impressed! The neck is SO smooth now! Its like the day I got it. I haven't got a chance to try it on the finger board yet, but It is some great stuff. I WOULDN'T try it on a bass that is wood with a gloss finish or any kind of paint though, b/c it is made for wood. It has to soak in. aka don't put it on you fender's neck, and then get pissed at me.