A neutral PH cleaner should be used. If this does't work, try a 50% solution of white vinegar to water and a brush. Be sure to clean with clear water after scrubbing.

If no luck, buy some Sulfamic crystals and mix and clean according to directions. Flush with clear water.

If no go, you will need to either scrape out the grout and re-do it or use a grout colorant and try staining it to one colour.

I used Simple Green with bleach added to it with a grout brush I bought at Home Depot. I had some old towels. Just sprayed the grout, scrubbed with the brush, then came back and wiped with the towels. Let it dry good then used a sealer, the grout looks brand new now. It is quite a job but worth it...

Oxy Clean! I sprinkle it on the grout then scrub it with a dripping wet scrub brush. It cleans it like new. While I was down there on my hands and knees, I scrubbed the tile, too. What a difference. I also resealed it the last time I did it.

I hate the tile floor and would never get it again.

I got tile floor because I thought it was supposed to be less maintenance and less of a hassle. But, if you have to clean and scrub the grout and then re-seal every year, I don't know if I would have ever gotten tile floors in the first place.

Don't use vinegar. It is an acidic product, even if it's diluted, and should not be used on grout.

There are inexpensive products out there that are alkaline based (Aqua Mix NanoScrub comes to mind) that will eat at the grout without doing damage over the long haul.

Also, the type of grout you have is important as well in respect to sanded, nonsanded and epoxy...

I've used baking soda paste and a brush to clean yucky grout areas. Rinse well. I tried chlorine bleach in another home and it yellowed the grout. I also had a heck of a time getting rid of the smell!

Do you remember if a grout with sealant was used? That seems to have made all of the difference in our current home. Use a neutral cleaner for mopping. I use Bona or a steam mop with plain water. I'm sorry you are frustrated and hope you find a solution!

Whatever you do, seal the grout joints after they are repaired. Seal them multiple times and make this part of your home maintenance schedule. When sealing, repeat the sealing process until the joints soak up no more sealer. This depends on the product used. I prefer a looser penetrating sealer, but many of my peers prefer a thicker sealer they claim seals with fewer applications. I have seen problems with the latter pealing/flaking.

Floorman:
What type of sealer? Where to buy?
Thx,
Betsy

You know? Blue dawn works for lots of cleaning jobs. I remove oily stains from clothing with a little dab of dawn gently scrubbed in. It also works great on skin oils that get deposited around cuffs and collars of light colored garments...it's great stuff.

However, regarding flooring...

A poster said, and I quote,...'I hate the tile floor and would never get it again.' Tile or stone floors are not for everyone and neither are wood or any other resilient material. You have to know what you're buying. If you've got cleaning issues, i.e. you want the floor to clean up easily and totally, you cannot beat a quality sheet vinyl or an equivalent material in the sheet format, because you can get it totally clean. Same thing applies...if you want a floor that is resilient, sheet vinyl or an equivalent sheet material can't be beat for comfort. And...if you want a 'natural' choice, then stone or wood is for you, although stone cannot be considered resilient. Porcelain and ceramic floors are somewhere in between, they are not strictly 'natural', but they are not resilient and come with cleaning issues for those who insist that their floors be completely clean when cleaned.