We spend a third of our lives on our bedding, leaving behind 56 hours a week of sweat, body oil and dead skin cells. So how often should we be washing away that funk, and what's the best way to do so?

Whether you sweat in your sleep, share the bed with a furry friend, or enjoy breakfast-in-bed, our sheets go through a lot. They collect dust, dirt, crumbs, hair, dead skin, and oil. So, it's ...