At home, I use orchid bark and/ or cypress mulch. For me, humidity is a huge issue, as I live in a super dry area and have to monitor it constantly.

In the stores we use either orchid bark or sani chips, depending on where the snakes are. If they're in tubs, the humidity in there can usually be kept high enough that using sanichips is fine. They're super easy to clean, which makes them ideal for maintenance in racks. The cages often have screen lids, or a basking light of some kind, so we use orchid bark in those situations, often in combination with moss and humid hiding spots.

-Jen