When BJ and Hawkeye catch Charles in the shower, only Charles' head has soap on it. With the next camera angle, however, his entire face is smothered in suds.
When Margaret and Nurse Harris are leaving the hospital, Loretta Swit's fingernails can be seen as roughly an inch long. As a head nurse, no way her nails could be that long.
If water is being reserved for the patients, then the doctors shaving should not have been allowed.