I had the chance to get some leg sinew a while back but was in a hurry and didn't clean it up very well. After drying it was looking kinda greasy and dirty. Seemed like drying squeezed out some of the oils/fat. I figures I would wash it in real hot water with dawn soap and then got side tracked for about an hour after putting it in. I came back and started cleaning it up and realized the sheath and fat would all come off with a little effort and ended up with some real clean sinew that should be easier to tear down when I do.