Be careful when using Potassium Permanganate, a little at a time , be aware that when you first put it onto the antlers it`s bright purple but soon calms down to a more subtle brown colour
Tip here is before you start to apply the Potassium Permanganate, cover the whole skull with kitchen roll and then wrap it in cling film, leaving none of the skull exposed, small brush, small amount, and dab it on again be careful as it runs like hell over the surface of the antlers, Oh! and don`t use it in the kitchen
Bob