There is cleaner which comes in a container which has a yellow plastic type bristle brush on the lid. I tried this last year and was surprised at how well it worked. It comes out as a foam. Thoroughly clean the rug first and then go to work. You may need to vacuum again after you have loosened the ground in sand. This product should be available at your local hardware or automotive store.
A water hose and broom or brusn.
Hi Robert, I found this online:
Begin by vacuuming away as much of the salt residue as possible. Mix a small amount of carpet shampoo with warm to cool water in the bucket. Apply the mixture to the carpeting using a soft cloth or sponge. Allow the mixture to set on the salt for a little while so that it can dissolve the salts.