DO NOT soak in bleach. Absolute worse thing you can do. It will be yellow in short order. Also, an ant pile is a total waste of time and you are about guranteed that a stray dog will drag it off. Your best option is to skin the skull, cut away as much meat as you can and then boil off the rest. Then you bleach with hydrogen peroxide. The stronger the better, beauty salons or beauty supply places have the strongest peroxide.
No dogs drug my skull away cus i had it under a milk crate and i bleached mine over two years ago still not yellow. It took bout a year fer ants n such ta clean it off except fer hair and then a day in bleach did da rest. But to each its own