I had a LOT of flagstone leveled and grouted. The workmen used gray fine
sand and Portland cement. They wiped as they went, brushing off the
concrete from the tops of the flagstone. They have been gone now for a
couple of days.

Things are looking white. I am staying off it for five days to allow it to
dry. Temperatures are in the 60s during the day, and 30s at night. The
grout seems to be going out into the flagstone, but only slightly. Not
really markedly, or in big strips.

AFTER I let it dry for a few more days, what's the best thing to do? There
is still some scrap sand on the surface, which will clean up with brooming.
Should I wet it down? Should I try to broom it wet to cut down on the white
lines? Is there an additive or spray I can put on it? Like vinegar of
muriatic acid?

What would you do?

Steve