Rick, sorry for the late reply, i rarely ever get into this forum. I was told about using antifreeze for snakeskins also.
I was told to flesh the hide well, then gently roll it up loosly, put into a gallon sized jar, pour fresh anti freeze in to cover entirely, leave the lid slightly loose for about a week. I did everything to a T.
I rolled the jar everyday so there could not be any dry spots.
The hide spoiled in the jar, I lost a very nice 5.5 foot copperhead skin, The next one I will use Alum powder.
I guess what I am saying is test any home recipe on a scrap hide, instead of losing a real nice one like mine.
John