A dust cloud, much like smoke and flames pouring out of a vehicle can be done with cotton batten that was been airbrushed. Unfortunately in 99.9% of the cases where I have seen this used it does not look very accurate, it looks like, well spray painted cotton. What you are trying to duplicate here IMHO is one of the hardest to achieve in modelling. The larger the scale, the harder it gets too.
Happy Modelling and God Bless
Robert