That's funny. A couple of mechanics at my LBS told me that hosing down with gentle water pressure was perfectly fine. Lube on the chain was the only thing they said I should pay attention to - do apply lube at appropriate intervals, but don't put too much. Granted, this is not an oceanside city - we don't have to worry about salt-laden mist or anything like that wafting onto our bikes here.

Everyone at the LBS, even the owner, treated fenders as optional things.