Maybe, maybe NOT!
Heh heh, we'll talk this to death by the time we get fully on the same page!
Why would going straight (as opposed to in circles/arcs/ovals) cause a larger scratch? Now I'm confused
FWIW, I'd move the mitt in short, jiggling motions like a, uhm....jitterbug sander. And I'd have the mitt full of wash solution and I'd stop to rinse/dunk/refill mitt as soon as there wasn't a *LOT* of shampoo mix there (it'll seep out of the mitt and help flush away dirt during the pause-and- "jiggle" motions). The more shampoo mix you have there the better- better lubricity and better flushing away of dislodged dirt.
Hey, I like discussing washing, it's sorta my thing when it comes to detailing....don't mean to drive you nuts or anything.