Tim ,
I was taught the same thing.
Alan Downes told me last time I had a service that the INOX tended to be absorbed by the insulayion around the wires making them swell.
He said that you can even give the motor a light speay with freh water if it is salty , but to be very sparing with INOX.
I havent been game to stick the hose under the cover but.
Brendan.
I do get through a heap of INOX on the wheels and brakes , and the reels get a bit too.