I honestly don't know how many form members hunt and/or live in rural areas, but I know in my case, I always seem to have a surplus of deer hides. Most folks I know who hunt and processes their own meat, toss out an incredible pile of materials: antlers not deemed worthy of saving, bones, hides, sinew, etc. I see our roadsides littered with discard piles and it drives me crazy. I'd encourage anyone who doesn't have access to harvested materials to reach out to a hunt club or perhaps a neighbor who'd be happy to hook you up with a skin. And if just going for rawhide, the process is pretty easy...
I suspect you're going after rawhide chew for convenience, but it's a pet peeve of mine to see hides go to waste so thought I'd mention it...
BTW I often degrease with a soak in borax (20 mule team stuff) followed by dish detergent.