Flooring Tile - removing grout from tile

Is there a safe way to remove excess dry grout from tiles?

depends, if they are porous tiles and were not sealed prior to grouting it will be tough. If is is just a haze you should be able to dry buff it off.

Dry buffing is not doing it. Is there any product that can be used?

Dried grout is dried concrete. It is next to impossible to remove. Do not use steel wool or metal scrapers. Some have been successful wetting grout and forcing off tile with oak sticks, wearing rubber gloves to prevent splinters. Sticks can be resharpened as they dull. Others report success using nylon scrubbie.

Textured and rough tiles, as well as unglazed tiles are best treated with a grout release product prior to grouting. Excess grout should be wiped up while still wet.

On my very first DIY tile job about 25 years ago, I had the same problem when I grouted unglazed quarry tile with black grout. The only way I was able to get it off was to use muratic acid (DANGER, Will Robinson!) full strength. That , in turn, leached most of the color out of the grout. I fixed that by using a solid color stain applied with an artist's brush to the grout joints. What a pain!
I think you should only try this as a last resort and then try it in an obscure area. Above all, BE CAREFUL, BE CAREFUL. That muratic acid is some pretty tough stuff. When I did it, I was dressed head to foot in rubber!

Bruce

I would try some white vinegar and a stiff brush before you go the acid route. Just remember to rinse it well afterwards.

I would proceed with caution using acids on glazed ceramic tiles. Unless you have a tile that is rated for acid resistance, you may end up with a dull finish on your tile.