I just put 2 skulls in a 35 gallon trash can full of water. Its starting to get pretty ripe
. My taxdermist recommended this vs boiling cuz it doesnt tend to crack the skull.
Just change the water a few times, scrub it and then soak in DAWN liquid soap for awhile. Should come out nice and clean.
I have another that I was thinking about burrying also, but wanted to see how this way works