I bought several large pieces of mopani driftwood. I used a 50 gal Rubbermaid trash can to cure them and they just fit. Since they were large it took about 3 months to cure them, and initially I was making daily water changes, using hot water. Later on, I'd use rock salt, and finally bleach. Do not ever use rock salt and bleach together. It was a long haul to get it cured, but it was worth it. The mopani looks fantastic in the tank.
Give it a couple of more months, and you should be fine.