I have an electric guitar, and its fingerboard in is rough shape after years of barely touching it and being lent to my younger brother (big mistake). I unfortunately don’t have an instrument shop close, so I would have to order oil for it, and even the closest one only carries like 1 or 2 kinds of string kits and a few arranger keyboards, not cleaning products.
While I probably could get mineral oil (not at the moment of writing this, due to weekends), I’m wondering how well cooking oil would work. Tried some grapeseed oil on some other piece of wood, where it wouldn’t be a problem.
NOTE: Likely will go with the mineral oil, so I also have something to clean strings with.
Linseed oil is a good choice because the oil will partially polymerize as it oxidizes. Tung oil is also excellent. Most commercial products are a blend of these.
I recommend this also, but put a REALLY thin coat on. Like you should think you’ve barely got any on, and you should then wipe it off and think you’ve wiped too much off. There is a lot of bad advice out there about these oils. You can put more coats on if you think it needs it, 24 hours apart. If you put too much on, it will tend to look matte, or worse, get gummy.
Preach!