I tried two methods about 20 years ago with horrible results.
The first method was the sun and salt method. It failed because I could not keep it stretched taught enough, and I lacked an implement sharp enough
to scrape off the flesh properly. Another problem with this the hide becoming stiff and rigid.
The other method I tried was the "wet" method. I prepared the hide with alum powder, rolled it, and placed it in a Borax solution, shaking the
bucket as directed on the instructions. All I got was a mouldy hide.
My brothers-in-law and their friends use, I think, kerosene and battery acid with better results, and the hides are more pliable, but smell of
kerosene. In any event, this still didn't give them professional quality tanned hides like you might find at some trade show.
Good thread, I think I'll Google for some tanning techniques.