Sakcrete can be used without water if the ground has even a little moisture. I have put in many primestar poles dry by tamping the stuff into the hole with a crowbar with a big washer welded on the little end. Had to be carefull not to turn it while aiming but in a day or two it sets like ... well like concrete. Even worked on the big (10') dishes if allowed to set overnight before putting the dish on the pole. Just dig yourself a trench, put in all the rocks you can find to fill it, then tamp in bags of gravel mix. Wet the sides and bottom of the trench first if it is really dry.