I asked a friend to let me clean, degrease, and whiten his mule deer skull that he killed in the fall of 2015. I told him after he killed it to put it outside for the rest of the fall and let the maggots eat the brain. I told him he should try and remove the rest of the flesh by simmering before winter. Well, he never did anything to it. It sat outside under his boat for one winter and summer. Then he moved it into his non-temp controlled garage until now. He lives in eastern Washington where it is a desert climate and temps in the summer were as high as 110 to 115 at times. He brought it to me a couple of weeks ago. Good news is the maggots did an excellent job at removing the brain. Bad news is that the remaining flesh and membranes are dried on there like a grayish brown hardened leather. I put it into the maceration process Monday the 4th. I changed half the water 7 days later on the 11th. It is in a fully insulated tote with an aquarium heater (new 80 deg fixed kind from wallyworld) and another tote over the top for a wind cover. I check on it occasionally to agitate the water and make sure the heater hasn't crapped out. I think temp is OK because it is steaming when I lift the lid. I have been getting a fuzzy mold growing on the antlers but I wipe it off with baby wipes. There are small bits of flesh coming off the skull and it stinks which tells me there is bacterial growth. But, after 12 days now the lower jaw has not separated into two pieces (even with a little force) and the membranes tight to the skull are still stiff and wont come off with a little scrapping. Does this sound normal? Would putting it in some heated or simmering soapy water help loosen it up? Should I just keep letting it macerate until its done?