Re: Got one for ya's (string related)
Use polymerizing oils, not the lemon sh1t dunlops sells. That thing has more solvents in it than oil and after time it evaporates completely. I use a blonde gunstock oil with all my jobs, the feel is superior, once you try it you immediately know how a dried up fingerboard feels. As a bonus, all of my customers love it and usually come back for more

The polymerized film helps to isolate the crud and sweat introduced by fingers, so that it doesn't get all sucked into to the wood. It can be easily cleaned with naphta to get the surface ready for oiling again.
Rosewood is especially complicated when it comes to moisture, so it's wise to season the wood properly periodically. But it's naturally an oily wood so it darkens over time and if your fretboard dries up you might not even notice it by eye. But dried up fingertips tell different story
Stay away from lemon oil it's more of a cleaner than conditioner, reall. Buy gunstock oil, the price is just the same, and gunstock oil is the real deal. If anyone insists on using only mineral oil, not the polymerizing type, then go to a grocery store and buy clear mineral oil for oiling kitchen cutting boards. But that won't seal the wood permanently and your finger will soak it up over time.