I've only used maceration and natural decay, which is unpleasant and messy.
And for the record, I personally prefer my animals alive over dead. I'm not a fan of trophy hunting really. Hunting to eat, playing by the rules, I have no problem with. But killing just to kill is putting unnecessary pressure on wildlife, just to hang it on your wall. I am not a fan off that thought process. Not trying to make a debate, just thought I needed to say that here.
Most the skulls I have acquired were either found or processed from road kill. I will admit though that I have a few that I acquired when I was younger that were likely a result of hunting. I try to stay away from that industry nowadays though. Not trying to start a debate, just don't want my stance confused. I only shoot animals with my Nikon.
For the record, I have nothing against hunters who respect the land, the animals and the law. Its the poachers and idiots who kill just to kill that urk me.
Anyway, skulls are cool. A few years back I bought a human specimen from the Bone Room in Berkeley. I would like to acquire another.
Bart
No, its legal to own human bones and skulls, it all depends on how they were acquired, but believe you me, that receipt is in my safe.
http://www.boneroom.com/faqs/bones.html#bonelaws
Bart