Good day,

I have an 8 year old shower with ceramic tile. The city water has a lot of iron which has stained the grout in the shower. I'd like to clean it and/or re-grout large parts of the shower.

Has anyone worked with any of the acid products which supposedly eat away at grout? Home Depot has a product which contains sulfamic acid which supposedly eats away at cement and grout.

I had also thought about using a rotary tool like a Rotozip or Dremel with their special grout attachment but that seems like it could be a lot of work and it might be hard to keep the blade from scratching/cutting the tiles.

Any other thoughts?

Thanks for the assistance!