I bought a product called Plasplugs Grout Cleaner and only now notice that the label says "Do not use on grout joints of tiles that contain lime e.g. marble tiles". Is ordinary domestic grout likely to contain lime? Do you think I'd be safe enough using this stuff?
Be careful if you do this. I was a bit enthusiastic using one and I ended up damaging the seal. Water soaked in behind the tiles and it has just cost me a couple of hundred €s to have it repaired