Cliff Pickover mentioned this stuff on Twitter. Volcano Dust is powdered bhut jolokia, one of the hottest chili peppers on Earth (125 times hotter than a jalapeño). In the current issue of MAKE, we ran Gabriel Nagmay's article on how to grow your own bhut jolokia peppers.
Mark Frauenfelder is the founder of Boing Boing and the editor-in-chief of MAKE and Cool Tools. Twitter: @frauenfelder. His new book is Maker Dad: Lunch Box Guitars, Antigravity Jars, and 22 Other Incredibly Cool Father-Daughter DIY Projects