Selenite is known for being one of the few crystals that never needs to be charged or cleared. It naturally cleanses itself and all things around it. These charging plates will charge and cleanse anything you put on top of it. I would still, however, recommend putting this out in the moonlight every once in a while to amp it up a little bit. Just make sure to never get your selenite wet, as it will dissolve in water!
DO NOT GET WET. Selenite will dissolve is exposed to moisture, so please take extra care to keep dry at all times. And I would not recommend place this in or near your bathroom.