Bioactive substrates question

Okay, so I'm currently reading The Art of Keeping Snakes by Vosjoli, the one with the stuff about BSS (Bioactive Substrate Systems). At one point, he states, "Whether you purchase a commercially formulated bioactive substrate for snakes or make your own..." This really got me interested. Does anyone know of any commercially formulated bioactive substrates? Vosjoli doesn't mention any by name, and I've searched the net to no avail. If anyone could help me out here I'd appreciate it, I'd like to transform my Okeetee corn's abode into a naturalistic viv soon and would save a lot of trouble if I could just buy the substrate.

From what I've read its basically just buying them separate and mixing it yourself at home. It saves you going out and actually scooping it up yourself. Homedepo or Lowes sell the playsand, dirt, and compost (dead leaves or what not). You'd have to pick up the rotting sticks yourself probably which has most of the organisms that would serve as your cleanup crew. Just be sure anything you get has no chemicals or fertilizers in it.
Hope this is somewhat helpful