Just a quick question for you...what more would you need to do before you'd classify it as being anal out of curiosity?...lol
Not having a go at you by the way, just having a friendly dig. Good on you for looking after your gear like you do, i couldn't be bothered going to that effort of cleaning something myself
To be Anal I'd do that after every trip, short or long.
I bought the Kamper second hand, the previous owners hadn't bothered to keep it "clean", so red stains on all the unpainted surfaces and they couldn't sell it, was on the market for around 6 months. When I had a look at it I was happy that the canvas was "as new" and all the Kamper really needed was a good detail, I got it for around $5k less than they where going for at the time. So the lesson here is a bit of time spent cleaning and maintaining will pay off come sale time :-)
PS That Rust and Stain Remover stuff is the ducks nuts for getting red stains off gal, spray it on, leave for a couple of minutes and hose it off, done.