Chlorine Dioxide does exist--at least as a semistable gas. It is used to destroy biologic contamination in the medical field (allows for sanitation of objects that can't take the heat of autoclave) as well as being able to clean up "spaces". The most recent public use was on the senate office building when the anthrax was released in there. They literally filled the building with the stuff. Kinda like a giant bug bomb. The gas fairly quickly decomposes into more stable (and safer) chemicals which disappate. So there is no residue other than some water vapor (this makes it pretty handy stuff).

I know Aqua Mira is using the technology, and I don't have any experience with ClO2 in liquids--but I know for sure it kills Anthrax spores (which isn't easy).