Lime Sulfur
Lime Sulfur is used by bonsai hobbyists for preserving and bleaching deadwood on bonsai.
Apply undiluted to dampened deadwood with a synthetic bristle artist's brush.
Best results are obtained when applied in full sun.
Remove excess from bark immediately with a damp cloth or paper towel.
This is a more concentrated solution than the regular garden nursery product.
Use with extreme care, eye and skin protection recommended.