I recently washed my Marmot Helium at home and it worked out really well. I live in rural southeastern Arizona so our water comes from a well and is quite hard. I used Nikwax Down Wash Direct for the job and was pleased with the results; the bag was really dirty having had about six months worth of use without washing.

The washing went as follows:

Wash cycle. I washed my bathtub thoroughly, then filled it with about 6" of warm water and mixed in the proper amount of soap. I turned the bag inside out and then slowly immersed it in the water carefully squeezing all of the air out. Getting the air out took a lot of time and effort but I think it is important. I then worked the soapy water through the fabric and down for what seemed like a year but was more like 30 minutes in reality. Once the washing was done, I pulled the plug in the tub and let the water drain then gently squeezed as much dirty, soapy water from the bag as I could. The water was pretty bad. I didn't try lifting the bag, rather, I folded it over on itself and pressed the water out against the tub bottom.

Rinse cycle. I rinsed the bag in three changes of clean, warm, water trying to move as much water through the fabric/down as possible with each rinse. This took about an hour and was a lot of work. After the last rinse I squeezed as much water from the bag as possible gently folding and then rolling the bag into a wet ball. I rolled the "ball" onto a large towel for transport to the drying stage.

Drying. Using the towel as a supportive sling I carried the bag into our laundry room and then carefully lowered the load into our top loading washer. I very carefully distributed the bag around the bottom of the washer tub and then put the washer on spin cycle for ten minutes or so. The bag came out of the spin cycle with no free water inside. I then put the bag in our dryer on the air fluff setting. There is no heating of the air with this setting. It took about an hour and a half to dry the bag. Keep in mind, though, that the relative humidity was about 5% the day I did this; you'll need more patience if you live in a humid area.

I just got back from an overnight trip using the bag. It was back to it's original loft and smell. Before I washed it it was greasy, rancid and had lost half of its loft. Now it's like a new bag!