If you were to make a wireless shower head, would it have hydrogen molecules and suck in the oxygen from the air to create water?
Would you have to recharge it with hydrogen?
H2 and O2 tanks big enough for an entire shower would be quite bulky, especially because you'd still need to combine them quick enough to produce a steady stream of water but slow enough to not just burn the flesh off your bones (it's rocket fuel after all).
If you use fuel cells as a "reactor" you could power your house with the shower, though.