Dear Jim:
We travel to Arizona in the winter. The drive back is almost always difficult.
We just go to a car wash and use the high pressure wand. We don't use the brush. We don't dry it.
It works great for us, BUT, we may have different expectations for cleanliness. From day 1 we followed Cary's advice to avoid touching the teardrop, to use alcohol to remove finger grease, and to leave it alone so that it will patinize. We have never walburnized or polished it in any way.
When we picked up our Campinn, Cary pointed out another older one to us that was beautifuly patinized. That is our goal.
The only problem we have ever had is getting home in below zero temps, and having all the car washes closed. In that case we just wait until the temps rise and car washes open again.
I hope this is belpful.
Lorie