By just letting the rot happen, all the details remain. Folks like different stuff though. I would say soaking in dawn water killed off any chance you had of maceration cleaning it off. Embrace the stench and use only water, no additives. After the rot happens and skull is clean without having to pick a single thing off, then use a garden hose and rinse off. Then soak in warm dawn soap and degrease that way.
Assuming the elk head was skinned prior to attempting to rot? I find elk meat rots faster and cleaner than deer do.
+1 except I use acetone for the degreaser then the 40 volume peroxide
