How often you clean your grout joints depends on how dirty your grout gets. A pale grout on your hallway floor is likely to stain more than a darker grout on your bathroom walls, for example. That said, we recommend you clean all your grout joints at least once a month, to keep them looking their best. You can use a specialist grout cleaning product or make your own at home. To make your own, make a paste using two parts bicarbonate of soda to one part water. Spread this over your grout joints and gently scrub with an old toothbrush. Spray over white vinegar and scrub again, before rinsing with clean water.