If dried grout reside does harden onto the tile you can try to remove it using vinegar a chisel or a diluted sulfamic acid solution.
Chemical to remove grout from tiles.
Grout is incredibly porous like a giant sponge which means it will absorb any grease grime oils or spills it comes into contact with says leslie reichert green cleaning coach and author of the joy of cleaning and while the culprit may vary from room to room mildew in the bathroom cooking.
Leave the sugar water to soak into the grout for about two hours.
When that day comes remove the grout and replace it to rejuvenate the installation and make the surface gleam.
Don t mix the vinegar with baking soda or any other cleaners or it could cancel out the cleaning properties of both ingredients.
Sugar water method.
To purchase this chemical for grout removal consult your local hardware store or building supply store.
Muriatic acid a form of hydrochloric acid is a tool brick builders sometimes use to remove mortar.
Stir until the sugar fully dissolves.
The acid free formula is safe for ceramic marble and porcelain tiles.
If your tile is porcelain or ceramic try a vinegar solution to remove grout.
Pour the solution over the grout or apply it to vertical surfaces with a sponge.
Use white vinegar to clean stains out of the grout between tiles.
Mix 1 cup of white granulated sugar into a gallon of hot water.
Fill a spray bottle with half vinegar and half water.
It can also be used with a grout steam cleaner for extra cleaning power.
If you have yet to remove all the grout haze continue to method 3.
Spray the tile and allow the solution to sit for a couple of minutes before wiping it away with a clean cloth.
Cleaning grout off tile with vinegar is safe and efficient for ceramic and porcelain tile installations and grout but acid cleaners should never be used on porous or stone tiles which includes vinegar and rubbing alcohol.
The same or stronger chemicals can be used to remove grout.
Sugar and water method.
In some cases you can enlist vinegar.
To use you spray it on wait for one to three minutes then use a brush to loosen and rinse it off.
With tile the difference between dingy and dazzling often comes down to the grout in between.
Remove and replace grout even the best tiling jobs show their age eventually.