After it dries, take an old toothbrush, and gently rub along the dirt to knock the mud off. Then vacuum the area, going over the spots slowly twelve to sixteen passes. It depends on how powerful the vacuum is as to how well it picks up the sandy remnants from dropping down.
If there is a stain left (which we have not had, so far), do a stain removal.
Stains on the carpet If there is a stain on your carpet, try this stain removal trick.
A good stain remover is to make a mixture of baking soda, a drop of liquid detergent, and white vinegar in a large container and pour onto the carpet. OR sprinkle the baking soda into the carpet, then add the liquid. Work it in gently into the carpet and let it sit for some minutes, then get a towel and push down to draw the moisture up with the stain. Keep wicking the moisture until no more wicks up. Let it dry to see if enough stain is gone. If not, repeat the process. If there is still a stain - try these Stain Removers which might have better results for certain stains. PR Think GreenSave Your DrawersFridge FailureClean From the Top Down Laundry Tips Candle Wax Clean your Appliances Unclog Sinks Cardboard Cleaning