You already know about , but many also contain sweat, blood, urine and other bodily fluids along with mold and mildew. Unless you shower before bed every night, your mattress might also contain dirt, oils and trace chemicals from various toiletries, and even pollen.
Before you start cleaning your mattress, strip the bed and launder your linens. Wash and dry your first, then the sheets, and finally your bedspread/comforter/duvet. Check the manufacturer’s labels first and use the hottest water and dryer heat setting allowed since heat will kill dust mites in your bedding. While the washer and dryer are doing their thing, turn your attention to the mattress.
Most mattress retailers (from to ) will allow you to try out your mattress for up to 90 days, but they differ on the amount of money you'll get back if you return it. Other stores require an or , which can cost hundreds of dollars.