Tile grout can be difficult to keep clean because it's wedged between tiles where mops and sponges might miss. Grout can grow dark with time as dirt and debris fill the cracks between tiles. One unidentified man has found the perfect solution: By rubbing a candle on the grout in his bathroom, he coats it with wax, keeping it protected from dirt.
The video, uploaded in April 2015, shows the man rubbing a normal white candle into the grout between his tiles. Wax is hydrophobic, meaning it repels water. So coating your grout with wax will not only keep dirt from settling into the hard-to-reach crevice but also keep water away, preventing mold or mildew from growing.
Just make sure the grout is clean before starting!