I discovered this this past weekend as well. I added some dirty ceramic boards at the bottom of my Kamado barbecue to create a defractor and warmed the BBQ to really high temperature to cook pizzas. When I opened the BBQ the next morning I was surprised to see my stones being white as new. Surprisingly the other stone that was above this defractor is still as black as before but I guess because it was not on direct contact with the fire. Now I know how to clean my stones in the future. Thanks for the video.
I had a similar experience. Left my outdoor pizza oven going for probably an hour at high temp. It just cremates all the little carbon bits that find their way into the pores of the stone.
The stones on both are made out of coidierite. I don't see anything about the stones being toxic. I don't know why the process wouldn't work with yours, but I couldn't guarantee what it would actually do to the unit itself.
