I recently found out that Johnsons paste wax is mostly mineral spirits and carnuba wax, and picked some up to use as a bullet lube and noticed on the package it could also be used for leather. That jogged my memory from my youth, a gentleman made some SCA armor from leather, said he baked it with carnuba wax and it felt as hard as wood in my hands (and no it didn't look like a burned steak).
I did use some on a utility knife sheath for work, and threw it in the oven (with the oven off, it runs about 120-135) to speed drying from forming, it is pretty hard and has held up great for about a month now.
Does anyone have any other experience with carnuba and leather. I was wondering what would be a good way to test it in different ways. At $5.00ish a tub there is room to play.