Additionally, the pen was not an exact match for our backsplash or tile floor grout. After using it, the area we "cleaned" no longer appeared dirty, but it didn't match the surrounding grout lines ...

After, ensure that your tiles are also clean and free of any debris, and then mix your grout according to the manufacturer's ...

Nancy Birtwhistle offers a number of eco-friendly cleaning tips in her books, but how effective is the one for bathroom grout cleaning?