Fret board cleaner options?

You can clean the fretboard with lemon oil. I also use 0000 grade wire wool to get the bad gunk off (stroke in direction of grain).

I always take all the strings off. To keep a trem/vibrato unit in place I use a small block of wood, which tensions the springs. On my Washie, with stop tail, the bit that holds the strings is not held in by anything but string tension. Make sure that you have hold of it when you remove the last string.

Removing all the strings is fine- I always do, because otherwise I'd never get the fretboard clean. :-) Only time I change only one string is if I break one.

If you have a floating bridge, block it. (I have a nine volt battery, covered with duct tape, which fits nicely under mine to hold tension on the springs- find something that fits yours, and make sure it won't scratch or mar the finish.)

I never use anything on the fretboard, though- just wipe it clear with a soft cloth.

A damp cloth would also be fine, as long as you don't leave it damp.

Best,
Ande

I'm old school. Most of the time, I'll just wipe down the fretboard with a cloth (years ago I bought a big chunk of flannel from a fabric store going out of business for just that purpose). But if it's really in need of more than elbow grease, I use lighter fluid - it's a decent solvent, evaporates fast, and doesn't leave a residue. But it's not compatible with all finishes - so test it first on a small part that won't be noticeable.

I use a cloth and a product called Lizard Spit Fretboard conditioner. I am also a rabid fan (as in I hoard the stuff) of Lizard Spit Guitar Polish.

Sean