Oh, he does have dust - in 2014, the last time we saw anything from him, he showed micrographs of red/gray chips - the same he already showed in 2010. It's 2018 now.
Perhaps he is waiting, hoping that the samples go bad such that he at least can get an "inconclusive" verdict, which would allow him to not declare Harrit&Jones the fraud that that they are (and thus admit that he was complete fool, believing in the fraud for so very long). But that won't work: The usual pigments - red hematite, titanium dioxide, along with the usual fillers such as kaolin and silica, are perfectly stable, inert, and will maintain their chemistry and morphology for decades, if not centuries to come. The organic binders, such as linseed-oil, epoxy or other resins, do age, but retain their essential properties, such as the defining organic groups, for a very long time, too: Think of oil paintings that are hundreds of years old. They turn dark over time, but the oil finish is still oil finish, and every bit of such old paint is still amenable to forensic identification.