The reason you get more stoned off dry buds is because your plainly smoking more of it (burns faster) Dry bud is a sign that it has been exposed for a long period of time to the air thus deteriating the once lush bud.

water will only dry the bud out more once it drys, otherwise your just smoking wet bud. You cannot turn back the time on dry buds.

edit: If your going to try out an experiment I would go with a cool humidifier but dont let it get directly wet. Then you better freeze it right away or smoke it