Mop the floor with a kitchen mop, leaving the water on the floor.
Combine ¼ cup electric dish detergent and 3 ½ gallons of water in a large bucket. Sponge or mop the mixture onto the floor, over the already spread water.
Sprinkle silica sand over the surface of the tiles, mixing with the detergent solution.
Buff the tiles with an electric floor buffer and a clean cotton cloth, making several passes over each tile.
Vacuum the water and sand from the floor with a wet to dry vacuum.
Rinse the floor with clear water and vacuum away any dirt and debris with the wet to dry vacuum, drying the floor.