Hello,
My driveway is paved with red and gray bricks. Due to a porcelain tile
laying project on my front door stairs, some of the bricks got stained
with a diluted mixture of Keraply (R) (an acrylic latex dry-set mortar
additive) and porcelain powder (from tile cutting). How do I clean up
the stains? I called Mapei, the manufacturer of Keraply, and the
technician who answered doesn't have a sure solution. He suggests,
however, that hydrochloric acid (a.k.a. muriatic acid) may do the job
but that I should check with a masonry/brick laying expert.

Would somebody know the answer? Would vinegar also work? (I know that
vinegar is a much less potent acidic solution than hydrochloric acid,
but I simply have way too much white vinegar at home.)