Okay...one more option used by some bowyers and those that practice primitive skills to instantly 'age' wood, bone, even freshly knapped arrowheads and stone knives to a nice brown 'old/aged' color:
Potassium permanganate (KMNO3 ?) & alcohol solution.
It will make a new flint arrowhead look 5,000 years old (the patina effect). Counterfeiters love it.
You can get PP from local companies that sell/service water softeners - and from swimming pool suppliers (used by folks sensitive to chlorine). You can even use rubbing alcohol from the Dollar Store to mix it in. Doesn't take much in a bottle; maybe a tablespoon full.
Yep, wear latex gloves! It will color your skin a nice brown color too.
I seem to recall that Dean Torges uses it sometimes on bows. Hope this helps - rb