I have been able to get Georgia red clay out of our gray carpet using 409 (and lots of elbow grease, of course). Don't know about black dirt, but might be worth a try. (As far as I can tell, Fantastik and Simple Green are about or exactly the same as 409.) Although it is primarily a grease/grime remover, 409 will take mud stains out of clothing as well, when nothing else seems to work.