I'm looking for a classic tie on sling for my double - are they safe..?

By the looks of it the thong could slip out of the ends? Or are they as durable as other slings?

How are the rawhide best maintained?

How is the knot best tied so not to come undone while hunting?
Any pictures of good knots? I see Mickey have a picture of the knot, and I reckon I figured out how the thong is tied, but a loose knot would be nice.