I laid down some unglazed porcelain tiles a couple of months ago. When I was at the store where I got them from I noticed smudges on them, a good wiping later they were gone so I bought them. Long story short, I tried everything under the sun( tile cleaner,steaming, vinegar, impregnating sealer) and they work fine until the next time you steep on the tiles the smudges rReappear. Helppppppp!!!!!:help: