Somewhere around here I have a draft of a response I almost posted to one of the other discussions on lemon oil, though I decided I'd already said enough on the subject.
Nevertheless, since it's come up again... the key difference to me is whether you want to 'finish' or 'condition'. The definitions here are perhaps subjective, but Alembic finger/fretboards come 'unfinished' - just raw, sanded ebony (beautiful stuff).
To my way of thinking, if you want to maintain that, then you use something like pure, essential, lemon oil. On the other hand, you may choose to 'apply a finish' such as tung oil, linseed oil, or various other things - but once you do, you then have a 'finished' piece of ebony.
There's nothing wrong with that, but it is fundamentally different.
Tung oil leaves a deposit of material that bonds to itself, to form a harder surface (though not a vapor barrier seal). The polymerized versions of tung oil do the same thing, only a little better and in a way that is easier to work with.
In contrast, lemon oil just leaves some oils, that help replenish the wood and keep it from drying out, becoming brittle, and cracking or something.
Unless you drown the thing, it's hard to mess up with pure lemon oil. But you can most definitely end up with a sticky/gummy surface if you don't have much experience with tung oil.
So as Mica suggests, if you have someone do it for you, and you trust their ability, let them use what they prefer. But personally, I'm very happy to have a nice bottle of pure lemon oil on hand.
-Bob
