I posted earlier this month about how comparatively easily the black staining came off the front of the house with a bit of brushing. This before and after photo shows that we made quite a difference with a couple of hours' worth of elbow grease.
I didn't have the right tools, either. I think the wire brushes I brought were too stiff, and the broom I used was unwieldy. So I will bring a couple more bristle brushes next time we go.
We will have to see how the brushed spots weather over the coming months, but I'm starting to think that we will postpone the painting to next year, to see how well the brushing holds up.