I found one of them for petsmart online. This is for the husks by Exo Terro. The one by our house sells the compressed coir as well , same brand. It is supposed to be 100 % natural. I haven't had any problems yet. It is cheaper for me if I don't have to have it shipped.
Exo Terra Coco Husks Tropical Substrate - Substrate - Reptile - PetSmart
I don't use all that much of it now but I have a friend who grows other tropical fruit in pots with the coconut with success. With all the rain we get here in the summer I am thinking of switching to coconut coir or husks for them. Then I will prob. need to buy in bulk from somewhere online.
I will still keep most of the nanners in the ground tho. cuz they seem to love it.