What kind of wood is it (and what kind of guitar)?
I also have questions in this area. I have heard of Tru Oil being used ( this stuff ) - but what is it exactly? A linseed oil type finish or what?
And what of maple fingerboards? Lacquer looks pretty at first but it's not going to last, and that dirt from your fingers only looks good on a 1950's Strat owned by (insert personal guitar hero here). Epoxy of some sort??
What about porous woods with open grain that looks big enough to maybe interfere with a bend of a very light gauge string, is there some suitable pore filler for that? Epoxy again?
on EIRosewood I use the finest petroleum based oil I can find. usually just 3 in 1 but for a nicely grained board I recently used sewing machine oit that finer than that.
Liquid Parafins supposedly good.
as to maple boards, I dunno, I just don't like 'em, sorry!
Go to www.stewmac.com (Stewart MacDonald). They sell fingerboard finishing oil which works great for rosewood or ebony fingerboards. Normally you don't lacquer the fret board unless its a maple fretboard like Fender Stratocsters, etc. On maple fretboards you just spray the lacquer on the fretboard and once dry you scrape the frets. It's time consuming but that's how it's done and it works great.