Step 3: De-Fleshing with boiling or soaking
a. Start your water boiling. Reduce it to a low simmer and place your skull in. Cover with a lid if possible.
b. Check your skull as often as possible, about every 10-15 minutes. If you boil it for too long or at too high a temp, the bone may begin to separate along the joints. Once the flesh is soft and easily falls away from the bone, grab a pair of tongs and remove the skull from the pot. Allow it to cool slightly, but not all the way. Make sure you collect any teeth that may have fallen out from the bottom of the pot; you can glue these back in later.
c. Remove the remaining flesh by hand, either with gloves or without (I stopped using gloves because they get in the way too much). To remove what is left of the brain, use a bottle brush under running water; push the brush up into the skull cavity and basically brush & clean just as you would a bottle or tall glass. Keep rinsing, scraping & peeling until 90% of all the flesh is removed.
3. Soaking the flesh off of your skull. This takes a long time and STINKS but it has good results. Simply fill a Rubbermaid tub with water and place your skull in. It is best if the tub is placed in a warm shed, far from your house and from your neighbors house. Change the water every four to seven days as needed. The flesh will rot right off of the bone in the water. Some teeth may fall out but they can be glued in later. Time varies based on water temp and skull size, but expect this to last at least a month. Once you can see that all the flesh is gone, rinse under running water to remove small particles, and allow the skull to dry. I recently cleaned a deer skull in this fashion, and it can out with virtually no damage to the bone.