The water will not wash away the THC, because its not water soluble.
If your weed is wet, just dry it in the microwave. It also have the advantage of increasing the amount of THC, so microwaving your bud will make it not only dry, but also more potent.
(More details at : http://boards.cannabis.com/experienc...otency-mj.html
where several people tell their results doing so.)