If you run a backwoods with no water in it you run the risk of uncontrollable high temps. These cookers were designed to run with water in them. If you are concerned about soft texture with a water cooker, maybe you should look into a pellet smoker. It is a much dryer environment and you will be able to get the same texture as in your offset.
Red Valley BBQ Team Head Honcho ~ Vice Pres. In Charge of Production Firefighting BBQ Team ~ KCBS CBJ