That looks like binchotan charcoal, at least in style.
https://www.amazon.com/dp/B0774H38HX/?tag=tvwb-20
I actually just happened to see this today for the first time and had up pick it up to try it out.
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View attachment 17505
Ok it’s smaller than I thought, I could see that working ok.
View attachment 18802
Ok it’s smaller than I thought, I could see that working ok