I'm actually going to try doing some myself, my nephew got a 950 lb. moose this year and since he decided not to have the hide tanned (wish I could have) I cut a big chunk off, got as much fat trimmed off the back as I could and then washed in dawn dish soap and borax. Stretched and tacked it out on a board and put borax on it.

Next step is going to be dumping the borax and with cutting off some more of the dried up stuff. Then I'll wash it again and doing fresh borax - when it's done in a few weeks I'll cut a chunk and try to bleach it.