removal of grout from tile surface

Greetings!

Wow! Tiling is great fun. Rofl. Anyway, I have just finished grouting with a coloured grout from the H. D, waited the alotted time according to the box, now it would seem after all the gingerly scrubbing (like hell) and some minor scrapping (bull sh*te) all the wiping I have some left over grout on the tile surface (tile is slightly pitted for rock like appearance)
I've tried the vineger approach, I've tried the haze removal thing, befor I chisel it out with a framing hamer. Is there a better way?

Thanks for lstening, and responding!

Cheers

I just simply don't understand how this happens to so many people. Maybe tile isn't a DIY project afterall.

WHAT KIND OF TILE IS IT?

You may be able to use sulfamic acid crystals.