I'd be leary of using it without knowing what it has been coated/treated with. It appears to be very porous, and would require a high frequency of irrigation cycles. I think inert mediums with lots of watering cycles works quite well, (I use perlite and calcined diatomaceous earth myself) and have seen matted material like this made from coir used on NFT type tables. It would be interesting to see it tried in a container, provided it contains no harmful additives.
Roof ridge filter material.
I'm probably going to use it to rebuild the roof, so I will only chop off a small piece and soak some in water and some in nutrients and see what happens