Clean that gross grout lines for less than $30! Don't despair if your bathroom tile sports dingy grout lines. With this grout makeover tutorial, you have the ability to skip the need to retile an entire space—which can quickly get messy and costly—and instead use a grout paint pen to make the space look bright white again. The entire project takes just an hour or two to complete depending on the size of your bathroom. A home cleaning DIY must!