I'm a real novice. Have only done two backsplashes with glazed tiles. I attempted to correct a floor by regrouting. I removed the charcoal grout between the white octagonal floor tiles in a small bath in my daughter's house she recently bought. I dremeled it all out and then replaced the charcoal grout, but the tiles must not have been sealed, the grout won't come off the tops of the tiles and there is a gray haze on everything! I have scrubbed with nylon scrub pads until my arms would break! HELP!! Can this be saved?

what type of tile is it?

Try a good residue removing liquid, Fila make one, try that first.

Always start with the neutral remover first, and try a small test area first before overall application....Gaz
Residue Remover Neutral 1LTR

removing building site dirt, installation residues and any type of lime scale

Advantages
High performance on a wide range of floor surfaces
Cleans without damaging the floor surface
Highly biodegradable

I used black grout on hex tiles in my bath. It was pretty messy, but the haze remover that I tried etched the tile. Fortunately I tested on extra tiles. I finally used straight vinager, in a spray bottle. It takes some time, but the floor is perfect now.

White vinegar works well on most grout haze but ideally should be diluted.Try 10 parts water to 1 part vinegar first and go from there but check on an unobtrusive area first.