Trouble with gritty dirty tile

[Ernesto]

Yes, but then there's non sanded too.

 

[Nick]

I used Nail Polish years ago on sm jobs like baths ..

 

[highup]

This is new to me. I had no idea painting grout was an OK thing.

 

[ORLTG]

Actually the process of coloring the grout is called staining. It's best to hire a company to do this as the process can be very messy. Most professional tile cleaning companies offer this as a service.