Yes, I am using it now in my 90 gal planted tank.
I was lucky and got several jumbo size pieces, and I will say that they do look fantastic in the tank.
However, curing them was a long drawn out process. It took me several months to get them to where I could use them.
I used a large round Rubbermaid trash can to do the curing. I first started soaking them using tap water. At the start, the water would turn dark brown even before the container was full. After changing the water every day for about a week, it got to the point where it didn't turn dark brown right away.
Then I started by using hot tap water, and was right back where I started. I did that for about a week.
Then I used hot tap water and rock salt, again, almost right back where I started.
The I switched to hot water and bleach. After a few soaks in that, I started to make some progress. Now it took overnight for the water to turn dark brown.
Next I alternated, a soak with hot water and rock salt, a soak hot water and with bleach, a hot water soak.
Finally, after about 2 months of this, I got to the point where I got a very light tea color after several days. It was now more or less ready for use.
A few notes -
Most of the soaks lasted from 1 to 3 days, depending on how quickly the water changes to dark brown. The faster it turned the less time between soak water changes.
If you use bleach, do not mix it with any other chemicals, including salt. It's possible to cause a reaction and release chlorine gas.
I did this to several extremely large pieces. Smaller pieces would likely take a lot less time.
When I placed it in the tank, I used carbon and Poly Filter Pads in the filtration to keep the tannin color down for the next couple of months. Obviously I disagree with people that say carbon is useless or doesn't do much. As an addition note, I used a very high quality, for real, good enough for my reef carbon. Lessor grade carbons, especially some of the low price, common aquarium grade, carbons may give vastly inferior results.
Overall, it was worth the effort the Mopani driftwood does look fantastic, and I don't need to hang rocks on it, or uses other means to keep it underwater. It did take time to cure, and I admit that at times I was very frustrated that the process was taking so long.