I decided to try my own patience and see if I could wait about 5 weeks to let a pure Tung oil finish dry on a handle. I made it....barely. My Father's Day present to me. Spalted Maple handle with a 26mm TGN Finest knot, 50mm loft. Pure Tung Oil finish, then waxed.
I use tung oil on my oyster and clam knives and other wood handled kitchen instruments (spatulas). Easy to apply many light coats quickly, though I use the diluted (?) stuff. Looks fantastic on your brush handle, which has a lot more than tung oil going for it!