Cool tip Fatboy, I'll have to remember that.
I am more in dust that anything, I have been to chicken to go through big mud puddles as the extent of cleaning I would have to do afterwards. Especially if you play in a clay field like I do. That stuff stains and is so hard to get off.
Having a compressor is definately a life saver. It has helped to so many things, I could never list them all. Pumps up bike tires and balls for the kids, helped tremendously to help build my real life rock crawler and fix all the others vehicles I have worked on, cleans the garage well with air, and even pumps up my kids inflatable pool!
As far as power washing (or washing with water in general) I think I still am going to watch my other friends do it for a while and see the outcome. I have noticed one of my friends who just started power washing for the first time had some running issues on both his rigs that he power washed last week.