You want to bring in the big guns for a cleaning like this - a stronger acid-based cleaner than the citric acid.

StoneTech Restore is what I have used. It's amazing. I learned about it on the John Bridge Tile Forum.

Here is a link that might be useful: StoneTech Restore

Thanks...I think my tile guy ended up putting the Miracle SuperSeal all over the glazed porcelain tile and grout on the floor of the shower and not wiping it up completely. There was a pale yellow glaze over the metal drain cover, which I could scrape off with my fingernail.

The tile guy at Home Depot said he never should have put SuperSeal over glazed porcelain, as that product is only for unglazed tiles. I think because it's a base of 2x2" tiles, he took the quick route and poured the product in to apply it, but didn't adequately wipe it up afterwards.

That combined with the buildup of fatty soap scum was just too much.

The Home Depot guy also suggested a strong acid cleaner from Miracle Sealants to dissolve the soap and the old sealer. Then he suggested resealing with TileLab's no-VOC grout sealer that you apply only to the grout and not to the tile. I'm going to call both companies tomorrow and see which one will last longer.

Thanks graywings...went back to HD and got the Miracle Sealants acid cleaner. I called them (it was the brand of grout sealant used) and they recommended the same thing.

Of course, since it's HCL, I had to wear gloves and an VOC breather, but it cut right thru all of the built up scum. What's hard is how that soap scum can build up in the texture of the glazed porcelain.

I had to follow it up with their mild natural stone cleaner to neutralize the acid. Now I'll let it dry overnight then reseal everything. It looks brand new and the grout looks clean and reconditioned. Amazing.