It’s not just your mattress that you need to keep clean, it’s your bedding too! This includes your pillows, pillowcases, sheets, duvet cover and duvet. Ideally, you should aim to wash your sheets, duvet cover and pillowcases at least once a week, or more if you tend to invite your pets into your bed. It is also suggested that you launder the duvet itself at least every six months and your pillows every four months.