We clean a lot of sand stone. Any form of agitation followed by rinsing will improve the situation. What we found was this, the stone would re-absorb the slurry in some areas leaving the floor with shadows. If you then seal it after sufficient drying time, you seal the soil in.
We invested in spinners for sandstone and the difference in the cleaning is amazing. One or two decent jobs will pay for the spinners.
David.