The best way to wash your Mission Workshop bag is with water (yep, just water). You can either rub the dirt off with your hands or scrub it off with a soft brush. You should be able to get most of the dirt off this way. If you feel that you need to use soap, use a mild soap and rinse the pack thoroughly to remove any residue. Don't use a dryer of any sort, just hang it up and let it air dry.