Yes, it can be used in the shower or with shaving foam (I think you need to let it dry for 1-2 days before connecting it to the charger and shake it to drain the water inside). It has a shower-bath symbol on the back.
Never tried that, but i rinse it every time after shaving and so far it did not break. So maybe i would not go scuba diving with it, but bathroom stuff is probably ok.