you sure it is dust from drying and not particles in your chemicals? I have been using Tri-X pretty much exclusively for the last 6 months, and get no dust at all, and my bathroom floor is usually dusty. If you are seeing it in scans more than by visual inspection, it might just be grain artifacts from the scanner.
I did once see a fair amount of particles in my developer from leaving the mixing beaker out on a shelf instead of in a drawer, and I don't think it would be too difficult to think it would have ended up on the film, though after fixing and washing it probably would have disappeared.