Tuning pegs for musical instruments are commonly made from ebony or boxwood, but in medieval times and renaissance they would also be made from roasted maple. Maple is a relatively soft wood, so the trick is to roast it, which makes it very light and porous, and then let it soak in a mixture of linseed oil and turpentine overnight. It soaks the oil in like a sponge, going from swimming on the surface to sinking to the ground when it's saturated. The oil hardens and reinforces the wood, kind of like epoxy stabilised wood.
How long does it have to dry after that?
Honestly, I don't know. I didn't expect to see literal air bubbles rising from the wood in the oil bath. That's a lot of oil, so I expect several months for it to fully harden. Maybe I can speed up the process with an UV lamp.
Linseed oil polymerizes very quickly. It probably won't be as long as you expect.