PetSmart sells Aquarium wood in the reptile section, called Mopani wood.
The wood is sand-blasted and pre-treated for aquariums, however has not been waterlogged and leeched of acids/tannins. It does not have any chemicals or pesticides on it, it specifically says for Aquarium use. Rinse it and Soak it prior to use, or do lots of water changes over time to remove the tannins. Perhaps ask a manager if you can pre-treat the driftwood in the fish system and sell it directly from the tank to customers. If it is pre-treated, it acts as an excellent source of biological media for someone struggling with new tank syndrome, and won't leech into their small home aquarium. The driftwood will have no effect on the larger PetSmart systems due to their 24/7 flow-through water change systems.
It is actually priced very well because its per unit, not by weight like most LFS. If you look regularly and purchase frequently you can find some real gem pieces. Any of the other woods at PetSmart are too porous and will float or deteriorate over time.
Good Luck!