DryOil (3.5e Equipment)
From D&D Wiki
DryOil is an alchemical solution that, when in contact with a liquid or a solution such as blood, causes that liquid to dry (desiccate) rapidly. One vial can dry a single gallon of liquid, but it is far more useful when coating a weapon or in use with an alchemical crossbow.
When a weapon coated with DryOil strikes a creature, that creature becomes dehydrated (see Sandstorm, page 15) unless it succeeds on a Fortitude saving throw equal to the wielder's attack roll.
Three light weapons or rounds of ammunition can be coated per vial. One weapon of any other size can be coated per vial. Items coated in DryOil continue to be coated either until 2 hours have elapsed or until they strike an opponent.
Cost: 100 gold per vial