Vinegar and water. Just like washing your windows, the use of a combination of vinegar and water is the best solvent to remove the film left by the grout. The vinegar and water will not leave any type of negative effect or staining on the tile or the grout joints. The natural cleaning ability of the vinegar, combined with the washing effect of the water, will present the easiest, cheapest and minimally harmful product for cleaning the surface of the tile.
Repeated applications of the vinegar and water may be required to accommodate the removal of the grout film over the surface of the tile. Continue the wiping and rinsing of the tile face with the vinegar and water, until the surface is clear and haze free.
The key to proper cleaning of tile, is to spend time removing the additional grout when it is fresh and still wet. If you spend time rubber troweling the surface of the tile repeatedly, when initially filling the joints, the cleaning will be much easier. The more wet grout you remove from the tile’s surface initially, the easier the final cleaning and buffing of the surface. Do not think that all the grout will be easily removed after it dries, it will not be that easy, once it dries; take advantage of the ease of removal when the grout is fresh.