I've done quite a few euro's. A buddy of mine is a taxidermist, he hooked me up with some powder you add to the boil and any fleshy stuff just falls right off. As in, I'm pretty sure you could boil for a little while, then grab an antler, and shake it clean. Reallllllllly slick way to do them.

A secondary method, is to boil in hydrogen peroxide. This not only cuts down on the stink, but bleaches the skull a blinding white, while aiding in flesh removal....

Like all those ascot wearin' feather flingers say.... "slow, and low..."
This holds true for duration and heat of a euro boil....