It’s a good point. I expect my pre-wash routine to address that. A snow foam that is normally alkaline or at least has pH buffers to address acids and dwell time to bring other chemicals into solution and a power wash to address salts.
I don’t think it takes more time or energy overall, but maybe I’m not fully understanding your process. I can’t see a savings if you are having to clean heavily soiled mitts later. Using several mitts would certainly make the wash go faster though.
I use 2 mitts and neither one of them are heavily soiled when the cars done, not even close. I use a foam cannon pre soak and rinse before a mitt ever touches the car.