I'm guessing he bleached the skull, cleaned the meat and grime off, bleached it again, cleaned it again, and repeated it until it was white. That's what my dad does. Or he could be fancy using those flesh-eating beetles.
I left it in the garage all summer after cutting away as much hide and flesh as I could. The insects cleaned up about 90% of what was left. Then I boil it for about 20 min. or until I can easily clean off all the little bits and pieces. Then peroxide wash with a tooth brush, rinse, scrub with Soft Scrub w/bleach, rinse, and let dry in full sun.
