I have showered with my S0 over 700 times and no problems.
I've only showered with my S0 a couple times, and always found the speakers to be 'tinny' for a few hours afterwards, but no permanent damage whatsoever. Guess I could have answered my own question. Just wondered if Apple say anything specific about the AW being exposed to soap/shower gel/shampoo and if those could be corrosive over time.