Hi.
A few months ago a guy came to change the colour of the grouting of the tiles in our shower. He didn't do a great job and then became uncontactable. One of the issues is that some of that coating ended up on the tiles themselves, and I don't want to damage the tiles removing that.
What compound can I use to safely clean the tiles?
Sorry I am not sure what he used, it wasn't a paint.
TIA