Some inflatable mattresses are machine washable. If yours is then you’re in luck. Simply toss it in the machine following the instructions that came with the mattress. If yours is not a machine washable mattress you’ll need to apply a bit of elbow grease. Pour some mild soap in a bucket or bowl of warm water. Take a clean cloth, dip it in the water and squeeze out until it’s no longer dripping wet. Gently wash the entire mattress with the cloth. Empty the soapy water and replace it with clean water sans soap. Using the cloth wipe down the entire mattress to remove any soapy residue. Let the mattress air dry. You’ll likely find it easier to complete this process with the mattress inflated.\r