I have a couple of animals back that I just want to do skull mounts on. I assume they have been thoroughly boiled but the skulls are fairly yellow so I assume I need to whiten them and somehow degree them. Can someone give me tips on what to do and what order to do it in. Do you whiten then degrease or degrease then whiten? What is the best way to degrease? I bought some whitener at the beauty supply store. How long do you usually leave that on? Sorry for all the questions but want it to turn out right. Here's the impala skull I want to do first.