I have full stainless on my car and I have washed them a couple of times with a pressure cleaner. The results are excellent with no danger of scratching the finish, but then I read that pressure cleaning was not recommended. I asked the dealer and he said that there was no way water would ever pass the spokes into the tyre but then I thought that probably the hub end of the spokes is not sealed and water getting in to the hub may be a problem.
Can anyone (Dave?) tell me why pressure cleaning stainless wires is not a good idea?
I don't know about the wheels, but apparently pressure washing can cause internal damage to the tyre walls. Maybe that's why it is not recommended.