I've known people who use ants rather than meat eating Beatles.
That's what we do. My wife is known by all her friends as the "Road Kill Queen". We have skulls and various bones of a shocking number of animals in our house, many of which were harvested from freshly killed animals (either ones I've hunted or ones we've found on the roadway).

We just set the skull on a fire ant hill, cover it with a bucket and a rock to keep critters from dragging it off, and wait. The ants take care of it for the most part. We don't usually bleach the bones, though, but the advice given above looks great for that.