Any machine WITHOUT AN AGITATOR will work. As has been explained in prior postings, the twisting can cause some damage. A LOCKED agitator is likely OK. I don't have one so it is hard to say. I have a newer machine without one, though it is a top loader. It is on delicate whenever I was my down stuff.
I didn't care for the front loaders, so didn't get one. The physics are wrong leading to amplified vibration and noise…premature wear. Gravity assists going spinning up(heavy) and resists going down(light.) They really want a concrete floor and heavy duty bearings…hence the term commercial.
I wash down fairly often. Once about every two weeks of use, depending. I dry it on a low heat setting in an electric dryer. Depends on your dryer. Heat is not that bad for down, but can easily destroy the shell material. Less than 140F is likely safe.
Use about 1/2-1/3 the mfg recommended soap. And a MILD, non-detergent soap. Well, most soaps are detergents to some degree. Woolite I have heard about being good, never tried it. I usually use down wash because it is cheap enough and insurance. Using small amounts means it will last a year or two. I often just add a couple tablespoons, since the bag is not usually dirty, it is more a little oily from my body, 'specially the hood. Sometimes my feet get pretty bad on longer trips, so, the bag will smell bad, too. Mostly water will wash that out.
Use the bag, but when you get back and start unpacking, it gets dropped in the dryer till I get the pack unloaded, replenished and a new "need to get" list thrown in for next time. Again, on a low setting…hmmm, also with three or four porcupine dryer balls. (Tennis balls work just about well.)
