I installed ceramic tile in my kitchen 3 months ago. I used a impregnanting sealer on the grout. The tile is glazed but with a matte finish. The grout is white and the sealer does not stop dirt and grime adhering to the grout which does not clean even with me on the floor scrubbing. Would putting on and additional membrane sealer or surface sealer make it better as far as cleaning. I just spent 3 days with a toothbrush and vinegar to get the dirt and grime off the grout and got it back to its original. This is my kitchen floor...high traffic area.