I like Old English Oil, lemon, readily found in the furniture polish section of any store. It has the consistency of water and will creep into the finest spaces.
I have a nice piece of driftwood I found 30 years ago. A year ago I noticed that it felt very light and seemed like it was getting "punky."
I used a new paintbrush to slather the wood with that oil and it soaked it up immediately. Did the same thing the next day. It brought out the grain in the wood and stopped its drying.
I've used it on rifle and shotgun stocks, and handgun grips, for many years. It's good stuff and very inexpensive.
I also like Howard Feed N Wax, made in Paso Robles, Calif. See their site at www.howardproducts.com
Their Feed N Wax is made of beeswax and orange oil and leaves a nice, dull shine on wood. The kind of dull shine that the old Winchesters and Colts had long ago, before plastic finishes became the rage.