I have two guitars I need to humidify, an electric and an acoustic. Both live in cases when not being played. Living in a hot climate where A/C is used most of the time so they are overly dry. Spent the previous two years in the desert where they got ever drier, so they're probably still trying to recover. Controlling the room humidification is not an option. What do you like for case humidification? I have used the "sponge in a bag with holes" option but obviously it's uncontrolled. Also, I worry a bit about the bag accidentally getting in the wrong spot and causing water damage to a guitar. What have you tried and liked (or not)?