Flooring Tile - Removing dried grout on tile surface

While I was grouting my backsplash I was called out on a family emergency. I did not have a lot of time to wash the tile with a wet sponge before I left. So I have a big mess on my hands.

I got the tile from Lowes. I'm not sure if it's ceramic. The name of the tile is ibiza bone. It is twice as thick as regular ceramic with a texture and a slight glaze. Most of the grout is in the textured surface of the tile.

How can I remove the grout without damaging the tile?

Try using a plastic scraper to remove what you can, then use a mix of 50/50 white vinegar and water with a WHITE nylon scrubbing pad. If that does on work, pick up sulfamic acid cleaner at your local home center or hardware store.

I tried removing the imbedded grout with vinegar with some success. However I am reluctant to use the sulfamic acid because of the sewer like smell.

Do you think spraying paper towels with the vinegar solution and leaving the paper on the tile for 2 hours may be a better way to go about this?

If the paper towels do not work, how long does the sulfamic acid fumes linger?

I almost completely removed the grout from the surface of tile using vinegar on paper towels and leaving them on for two hours. Now the problem is the tile is dull. Is there anything I can use restore the tile so it has slight shine?