TNhunter
Boiling skulls is alot harder than what you described.
I stopped boiling skulls about ten years ago and switched to using Dermestid Beetles. A Hot colony of Dermestid beetles will clean a dear skull in about three days and will leave all the intricate bone work, such as the nasal cavity intact.
But it is hard to keep a colony of beetles.
As far as bleaching. It is misunderstood about the bleaching of skulls all the time. Bleach will eat away at the bone over a period of time. What should be used instead of bleach is Peroxide. The Peroxide at the drug stores will not work. That is 3% strong. The peroxide they use for bleching hair is 27-40% strength and that works well without damaging the bone. You can get that at Beauty supply stores or over the internet.
Here's a pic of one cleaned with Dermestid Beetles and bleached with Peroxide.
I wish you luck in this big job!
classicfur