They just get dirty inside. But they still work as regular ear phones even when its not charged. I alternate between Cetraben and Aveeno but the morning after my skin is back to its good old dry self. These are very comfortable and super cute. I put my Sennheiser Momentums on the shelf for quite a long time because I lost the cable that came with them. I am more than disappointed at how quickly this flaw evidenced itself and now I have to wonder about the second pairs durability as well. This is so great! This item has not met any quaility standards as far as I can see. Earphone interface: 2PIN 0. Charges quickly and lasts quite a few hours.