Generally, spot cleaning your bag and letting it air out in the fresh air is usually the best solution, but you can wash it completely. For the safest and best cleansing option, we recommend washing down sleeping bags by hand. Damage due to machine washing by customer or other improper washing is not covered under warranty. For machine washing, let us wash your bag through Rainy Pass as they are our professional cleaning and repair service company for all Hyke & Byke outdoor gear.
If you feel that must personally machine wash, sleeping bags must be washed in a front loading washing machine. Do not use your home machine if it has an agitator in it. Agitators can tear sleeping bags. If you decide to machine wash, wash on a gentle cycle with warm water. Do not use the hot setting on the washing machine unless you are familiar with it. Scalding water can damage the fabrics on Hyke & Byke bags. Do not use your home machine if it has an agitator in it. Agitators can tear sleeping bags.
Dry cleaning is not appropriate for sleeping bags, especially down. Solvents used in dry cleaning can strip the natural oils from down that help it retain loft. Damage due to improper washing is not covered under warranty.
Washing needs to be done delicately and regular detergent needs to be avoided. Instead, for your down sleeping bag use something like ReviveX Down Cleaner ($9; mcnett.com) or Nikwax Down Wash ($11; nikwax.com). The natural down needs to be washed well and fully rinsed of the cleaner. Be sure to run it through the rinse cycle twice if using a washing machine. After the washing process is complete, dry your bag either outside or in a large commercial dryer. Drying is incredible important for down sleeping bags. If using a dryer, it is best to use a low heat for a long period of time. Similar to washing, avoid the high setting if you do not know how hot it gets. Continue drying on low until the bag is completely dry; this can sometimes take 2-2.5 hours.
I have detailed steps for both hand washing and machine washing that I would be happy to send to you if you would like further information.