+1 on Fret Doctor. I bought a small bottle about five years ago, and
used it on all (but one) of my collection of guitars, rosewood, ebony, baked maple,
they all seem to absorb the Bore Oil and take its sealing qualities into the grain.
Once a year seems to be enough. I apply it sparingly with a Q-tip.
Another fine alternative is Music Nomad's F1, an excellent fretboard product.
I use lemon oil very sparingly, mostly to clean a fretboard of grime and dead punk skin
before the real treatment with Fret Doctor.
Lemon Oil works for me as a cleaner, but I don't think it does much else.
It does no harm, unless you work excessive quantities of it down into the fret slots
where it can soften the wood.
On an old lacquered guitar with checking in the finish, excessive lemon oil can get worked
down into the tiny cracks and make them bigger. Not recommended.
By the way, in the Army they issue G.I. Bore Cleaner for weapons maintenance,
and that stuff is designed to dissolve powder residue and dislodge brass fouling from
military rifle barrels. Bore Oil is a much more peaceable compound... *grins
It's intended to sink into the bare wood of musical instruments, and protect the wood from
moisture, spit, grease from human skin, and airborne pollution such as smoke, greasy steam
from kitchens near the stage, condensation, girl perfume, and spilled beer.
The scent of G.I. Bore Cleaner can send even an old man right back into the barracks,
or the brig.
I don't use anything on my MIM Fender Tele, because its maple neck with integral fingerboard
seems well sealed with Polyurethane and never gets dirty, never has any issues, wipe it
down with a bandana after playing and forget it. Typical Fender tough.
A polyurethane finished maple neck seems impervious to just about anything.
You can oil it all you want, and then wipe all that oil off. It doesn't do anything.
You can spray it with polish, and wipe the polish off and the neck is unchanged.
Furniture products like Pledge are terrible choices for guitars, because of the silicones
in them. But a polyurethane finish won't be damaged by something as bad as Pledge.
Wipe anything off it, and it remains unchanged. Polyurethane seems like an excellent
and practical guitar finish IMHO.
You can spray it with fast fingers, and then rub all that off on your fingers, then wipe
your fingers off on your pants. *grins. The neck will remain the same. That's my experience
but I've only owned my MIM Tele for about ten years. I've seen Fender telecasters with the
Lacquer varnish worn right off, and the dirt and grime and finger skin rubbed right into
the grain of the bared maple. Those look dreadful to my eyes... yuck. But I don't think the
Polyurethane is as easy to damage as the traditional lacquer.