one point of mineral oil is to prevent body oils, dirt, etc. among other things from permeating the fretboard. That is the main purpose of oiling wood kitchen items, not maintain moisture levels.I polish frets...only if/when I do a level/crown. I rarely oil my fretboard and wonder if it is really necessary.
Has anyone ever actually tested it over 30 years or so? I don't think I've ever seen any evidence that soaking your fretboard with a petroleum distillate will keep cellulose and resin from drying out. I actually wonder if it accelerates it? Why wouldn't oils and dirt from my fingers be more effective at sealing moisture in?
And yet, I do oil my fretboards...
Imagine wearing the same set of clothes and socks for a long period of time without washing them. Aside from major spills, most "dirtiness" is from the human body. I don't want my clothes to smell like a gym locker room, nor my guitar . . . . Aren't human hands one of the dirtiest things out there?