Last season my boys drew youth antlerless deer tags in Chiwawa and 2nd deer tags for Benge.
I made a huge mistake while boiling the skulls from their Chiwawa deer in the evening. I fell asleep an the couch and when I woke up several hours later, there wasn't much left. Most of the plates had separated so I was left with just a huge mess. Lesson learned.
The deer they took in Benge (one turned out to be a small buck) I boiled several times in short sessions and picked meat off in between. After a day soaking in professional strength peroxide creme they turned out great. Bright white and perfectly clean.
BTW, we buried some a couple years ago with terrible results too. Black and brown stains on them that will not come off.