Problem with taking out Grout during installation of Ceramic tile


We just installed new tiles in the bathroom. Unfortunately, while applying the grout some made it on the surface of the porcelain tiles. The grout on the tiles was left overnight which is resulting in haziness and now needs to be removed. Tried a few things but the grout on the tiles is very stubborn and is not coming off. Any suggestions?
Tried Aqua Mix and am now trying Sulphamic acid. Anything else I could try and are there any tricks when using these that would make it easier to remove the grout without damaging the tiles? thanks.
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For haze try a WHITE 3m scrubbing pad with water. It will remove all but lumps without scratching the tile. I would be concerned that acid would etch the grout between the tiles making it weak and porous.

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