Here is what I can share with you...
I used to live in Alaska and would do very remote hunts for Dall sheep.
I stopped by a taxi's shop before my hunt and got his opinion of how to best preserve the hide for mounting later.
He told me that after skinning (and a decent job of field fleshing) to lay out the hide and dump 5 pounds of salt on it. I can't recall the kind of salt though, it wasn't table salt. Spread the salt around evenly and fold it hide to hide, not hide to hair. Once folded a couple times then roll up tight and tie. Given our temps at that time of year, that hide would easily stay good for roughly 10 days, plenty of time to get back. This is my only experience with salting hides.
HTH