I never heard of them either but one positive thing on their site that got my attention was:
Green Shavings, Ltd. Has teamed up with Callaway Farms Manufacturing, LLC to produce these new shavings
I have been buying Calloway Farms shavings for the last 3 - 4 years. They produce a high quality shaving for the same amount of money those crappy Tractor Supply shavings cost.
I would try the Green Shavings if my local feed store gets them in, PROVIDED they are in the same price range as Calloway's Triple Select shavings.
I have four horses who come in every night. I use a pallet of shavings (45 bags) every five weeks. I cannot afford to pay extra for the word "green", unless that word gets me another couple weeks out of a pallet's worth of shavings