I picked up a bottle of Dunlop Fretboard 65 Ultimate Lemon Oil today. The rosewood fretboard on my Gibson BFG was starting to look and feel a little dry. And since I had a gig tonight I figured I'd give it a little drink.
Fretboard 65 Ultimate Lemon Oil comes with a Dab-O-Matic applicator built into the neck of the bottle which is a nice touch. No disintegrating paper towels. Or cloth rags of dubious origin to deal with. No oily spills, no stained carpets, no fuss, no mess.
Contrary to the directions on the bottle, I didn't bother removing the strings. I just rubbed the applicator onto the fretboard over the strings making sure I got a thin, even spread on the fretboard -- the applicator ensured that just the right amount of oil was dispensed.
And boy did that fingerboard drink up that lemon oil in a hurry! The wet sheen of the oil was thoroughly absorbed within 5 minutes, leaving a dry lustre, showing off the color of the rosewood beautifully.
I've used Old English brand Lemon Oil in the past; you'll see a bottle on almost every guitar repairman's workbench. Old English is much greasier and my twice yearly lemon oil treatment with that stuff usually took a couple of days to dissipate. Fretboard 65 Ultimate Lemon Oil appears to be much lighter and more fingerboard friendly.
By the way, the directions on the bottle state that this product is not for maple fretboards. Maple fretboards are usually hard finished and can't be moisturized with oil. And if you've ever oiled unfinished maple you'll notice that it makes the grain on the maple stand on end, making it feel slightly rough and 'hairy'.
A final word of caution: According to noted guitar repairman Dan Erlewine, any mineral oil when soaked into paper or cloth towels can generate heat on their own and spontaneously combust after several hours! Dispose of carefully!
And here's my review of Dunlop Ultraglide 65 String Cleaner.