Can you not brain tan rawhide to get a normal leather type finish?
Yes you can brain tan rawhide. Although, only brain tanned deer is called buckskin.
I know several people who take those dog chew bones, soak them, untie and flatten them out, and then BARK TAN the various pieces. They take oak bark, chop it up pretty fine, make a sort of "soup" out of it, and the put the rawhide in it. The tannic acids in the oak bark then work there way into the raw hide, slowly turning it into leather. It is then usually called Vegetable Tanned leather. It does take a long time to work its way completely through the hide. And stir it occasionally. Check if it is "tanned" enough by cutting a little sliver off of one side to see how far the color has progressed through the hide. Bark Tan is one of the older leather tanning processes. It can take weeks to tan some hides - depending upon how "strong" your bark soup is, and how thick the hide is.
Most of the dog chew bone rawhide has been Salt Cured - or "pickled". It was soaked in brine as part of the whole process of being made. This cuts down on the problems with bacteria and mold on the raw hide until it is fully dried or cured. So they can be kind of "salty". Soaking them in several changes of water will leach out a lot of that salt.
And there are a whole lot of various "chemical" methods of tanning hides to get leather. A large percentage of modern leather is Chrome Tanned. The recipe should be out on the web somewhere. You are generally using acids to break down the cell structure a bit in the hide, and then working in vaious oils to replace the water and help make the final leather more flexible.
So you can tan some of that rawhide if you wish, but you would be trading a lot of time/mess in place of buying already processed leather. It's fun to do for the experience, but after that it becomes questionable on a small scale. The people who are generally doing their own tanning are doing brain tanning of deer hides to get buckskin - and then selling it at a premium price.
Mikey - that grumpy ol' German blacksmith out in the Hinterlands