I've heard pretty good feedback on Taraxatone by Cytodyne from my customers. You could then use Glycerol on the day of the show to pull the remaining water from beneth the skin into the muscle. Twinlab makes Glycerol Fuel, and EAS used to (not sure if they still do) make individual packets of straight Glycerol that you mix with water and drink. It was marketed under their "Neo Elite" label. Packs sold for under a buck each.