Machine Wash
You don’t want to wash your sleeping bag in a home washing machine. Instead take it to a laundramat where you can wash it in a front loading machine. A top loading machine can damage your bag. Your choice for detergent depends on your bag’s insulation material. For synthetic bags, a mild detergent or cleaner specially designed for synthetics is your best bet. Use specially formulated down soap or mild soap for a down bag. Srubbing the outside of the bag especially the head and foot area before washing is a good idea. Water temperature for washing should be warm, with a cold rinse.
Hand Wash
You can also hand wash your sleeping bag in your bathtub using warm water and mild detergent for synthetics and down cleaner for your down bag. Scrub the head and foot of the bag but be gently. You will not be able to remove every stain on the bag. After scrubbing is done, drain the water and press soapy water out of the bag with your hands. Keep the bag on the tub floor and don’t wring it. Refill the tub with cold water at least three or four more times to be sure all the detergent is rinsed. Leftover soap will cause the fill to mat.
Drying
Gently roll the sleeping bag to squeeze as much water as you can. Place the bag into a plastic clothesbasket carefully. Don’t lift from one end of the bag. Tumble dry in large commercial dryer on medium low heat. You may also put in some terry cloth towels to decrease drying time and minimize static electricity. A couple of tennis balls will fluff the fill. UV sun rays will damage nylon so you don’t want to hang your bag to dry in the sun.