Our new bathroom floor was grouted with Permacolor Select, bright white. I was told it did not require sealant. My tile contractor advised me to clean it only with Aqua Mix, and it has worked reasonably well. Regrettably, one of our pets threw up last night. I cannot get the yellow bile stain out of the grout. Aqua Mix has no effect.

I dug around on Laticrete's website and see they recommend Stone Tech products, so I will try KlenzAll, but I don't think that's going to cut it either. I know I can't use anything acidic on the grout. But I wonder if I could I steam clean the grout line with hydrogen peroxide? This was my tried-and-true method for cleaning my old grout -- 3% hydrogen peroxide in the tank of my Bissell steam cleaner -- but I recognize it is very alkaline.

Furthermore, to avoid this problem in the future, is it too late for me to seal the grout? The Laticrete website says that while sealing is not necessary, you can use one of three different products if you wish to have overkill: StoneTech Bulletproof, which I think I have on hand, or Stone Tech Heavy Duty. The floor has been in use about three months now, and the grout is still quite clean except in this one spot where the bile settled last night.

And advice is greatly appreciated.