"Baquashock" which is a swimming pool cleaner and is full of hydrogen peroxide works great. Costs about $55 - $60 from Farmlands or Wrightsons and comes in 5 ltr containers.
I use that to bleach skulls by painting it on with a paint brush and then letting dry.
Once completed I also put a thin coat of Danish Oil on antlers / horns and it comes up absolutely mint and seals in the colours!
Bookmarks