I washed mine in my washing machine. Problem I had was it filled up the washer and wouldn't tumble so I took it to the dry cleaners and had them was and dry it in their big machines. I just gave them the down wash to use.
I wash mine in front loader on gentle setting dont use hot water, I use down wash . then on lowest setting with tennis ball in dryer. High heat will destroy your down make sure you use lowest heat setting, takes about 4 hours to dry but puffs back up great.
I use Nikwax downwash in the bathtub and gently wash by agitating by hand. I have western mountaineering bags and don’t want to risk damaging them in a machine. This method works great. I’ve also down this using a 50 gal plastic trash can. Works well for washing packs to
I spent more time than I care to admit and in the end parts of it just wouldn't come back to life. I sent it to Rainy Pass and that and that is the way to go for me now.