Try doing a search using the term "rugbadger" and see what comes up. The Rugbadger is a machine designed to "dust" a rug, which is similarl to what they do before wet-cleaning it when you send a rug out to a rug cleaning plant. You can also approximate the results of a Rugbadger by turning the rug upside down, then running a vacuum cleaner which has either a roller brush or metal roller bar over the back of the rug. You can also do this pretty well with an OP machine like the Challenger.
Then you vac up all of the dust, sand, etc you have shaken loose from the wood or whatever floor, vac the surface of the rug itself, then clean the rug pretty much the same way you would clean W2W carpeting with your Challenger.