Morning all, i cleaned a patio a couple of days ago, it was all slate (first job on slate), I used the whirl away with my honda gx390, after the first clean it was disastrous, there were stripes where I'd gone up and down and circles everywhere, no problem I thought, just go over it again, after the fourth time! I let it dry completely, but having looked again this morning, there are still a dozen or so circles that just won't shift!
I didn't use any chemicals, any advice on how to get them off?