Picked up some of the same stuff a couple years ago from PS or some other box store. Regular mopani wood without any of that weird bark or any of that crap.
Gave it a good boiling in my wife's stew pot for about an hour to accelerate the tannin leeching, let it cool down and it's been in the tank since then. No film, no brown water and sunk like a Mob cement shoe. Didn't end up needing carbon or purigen either.
BL pleco made one of them his home and the other has multiple anubias stuck to it like glue.
The longer I'm involved in this hobby the more & more I'm convinced that Bio-Type species tanks are the way to go. Plants and fish/inverts live together in nature for a reason. I find the less I try to fight nature the better my tanks look.
- DogFish 1.24.12