I've been doing some test patches of this in my arena, which rides too deep. You mix the shreds into the sand. So far, it's performing well, though looks a bit scruffy. I am struggling to get samples out of some companies though, which is driving me nuts.
We have just added several bales of this to our outdoor school as the surface was wearning thin and shifting. So far it seems really good and is stabilising the surface.