I'm re-grouting a 225 sq/ft kitchen floor that the last guy didn't bother sealing. 3 years old, white grout, homeowner who wants it to stay sparkling white. It's really dirty, and she wants me to re-grout. I told her that the best option is epoxy grout, as it is non-porous and never needs re-sealing. I've used Grout Once! additive before and was not impressed with it's stain blocking effectiveness as I spilled my coffee while working and the grout soaked it up like nothing. So, she's OK with the $500 material cost - my question is, what can I tell her to reasonably expect? It's still white rough grout on a kitchen floor. Anyone with any experience?