Why would you want to keep it moist? You don't get the most active THC out of your weed until it's fully dried. I use tupperware or mason jars, and just keep it in a cool/dark place. Back when I first started smoking I thought that weed was better when I kept it moist or humidified, but I realized all that I was doing was making it harder to break up, harder to smoke, and more harsh. Nothin gets you ripped like bone dry nugs.