Leaving it on an ant hill means a dog can swing on by and pick it up.

For the putrification part, a 2 gallon ziploc bag filled with water, set in a 5 gallon bucket of water in a shed out of reach of animals. The inner bag contains most of the smell, and insures the skull stays wet. You'll need to top off the water in the bucket from time to time. I did this for 30 days.

In the boiling pot I had some detergent to get the oil out of the skull. Just don't boil too long or too high. You want to simmer it for 4 hours or so. Do this outsided. It is nasty. I've done 5 deer, my B&C Elk, and 2 bear this way.

After the skull has been bleached in a 20% solution of hydrogen peroxide (beauty supply store or your local mosque), I let mine dry for a few days in the sun to make sure it is "bone dry", and then I used clear acrylic floor wax to seal it.