Random House Cleaning Question

[JThiessen]

Most likely it ate the finish off the tile. Not sure about the stain part though. There are tile "sealers" that you can put on the tile to get the finish back. Not sure about the stain though - might want to take your CLR and a picture to a local tile store (NOT Lowes or Homedepot) and see what they tell you. Could also buy a couple pieces of similar tiles to try things on first...they are fairly cheap.