This is generally OK with several caveats. I have one at home that works really well.
Turn down the agitation level to as low as possible. I am not sure if this is really necessary, but "Delicate" (or "handwash") is fine on my machine. I hate to try any stronger and the bags don't really need it (once I had some pine pitch on it that took two washings to remove.)
Water does most of the actual washing with the soap just mixing oils with water to get body oils off. Soap also acts as a surficant, sort-of like a light dye replacement, for dirt and stains. With the HE washers, generally you cannot select water level. But, after a pause, you *can* add another gallon. I will often do this, but it isn't strict...sometimes I forget about it in the hustle and bustle of getting unpacked. Anyway, I use adout 1/2 to 1/3 the recommended amount of soap. IFF I have been out for a long hike (4 weeks or so) I use about 3/4 but never the full amount. I use a hot wash and hot rinse with an extra rinse. Then a wash and rinse with no soap added...just water...to insure it has been completely rinsed. My seetings are "Heavy Soiled" and "Deep Clean." I think this just increases the time to wash and the water to rinse, though.
I do our bags one at a time. Again, this allows the most water to wash the bags. I will also use the Nikwax's Down Proof. This will help a bit with water resistance. Much like a DWR coating for down. It will wear off after two or three washings, though. The first time is full strength. After that, I use a half strength mix as a touch up. This seems to work fine since we have had the machine, about 5-6 washings per year... The machine will add this automagically by pressing the "Fabric Softener" button after washing and putting it in the proper dispenser.
For bags, zippers should be "zipped." There is no agitator to catch and rip stuff, so these are fairly safe, but, they could damage the shell materials in the spin cycle. Maybe I am being too cautious here, though. I have a light pertex shell that is easily damaged. Inside out to clean the inside is mostly what I do, but even then, some stains will accumulate. DO NOT try to remove these. Stains are often embedded, like a dye, into the fabric and will require a detergent or bleach...never use either on your bag. Soo, I just ignore them. You can try wiping down a stain with Simple Green or the like. It doesn't effect down like bleach. But do not let it penetrate to the down. It is still a detergent. Small amounts on a rag and wiped quickly seem to do OK, but, I still think ignoring them is best (unless you are like my wife who insists a stain is not "clean"...I do our bags.) A detergent will strip any oils off the down. This leaves the down brittle and subject to breaking or clumping even when clean.
Carfully roll the bag into a roll to move it to the dryer and unroll it. Use two to four dryer balls (like porcupine quill covered tennis balls) and dry with LOW or NO heat. This will take a couple hours. Down is relativly impervious to heat up to boiling water temps, but synthetic fabrics (the shell,) plastic zippers, elastic cords & cord locks can be damaged. IFF you know you dryer gets about 130F on low that is fine. There is a LARGE difference in dryers!!! My wife has a stationary rack (sweater rack) for our dryer that reads 125F on low so that is where I set ours...Low. I have used commercial dryers that simply get too hot on low...YMMV. Generally anything <140F will be safe, but I would suggest 130F. Small, metal YKK zips can hold heat and possibly heat the fabric to damaging. Turn the bag inside out after the first hour. After drying, pick apart any clumping(I never found any) and hang the bag for a day or two. Or, since I hang our bags, I put them on hangers in the closet with the doors open for a couple days. Then you can put them in a bag, I never use the bags, though.
Reviv-X does not seem to get hot enough to work well on bags. It works OK, but, I have pretty much given up on it. I just rely on the fabric's fine weave to repell water. Maybe because I am too cautious about the heat? Using Down Proof, seems to help as much, but this will also wash out, so, needs to be added back after washing, though not as much as the first application.
The agitators in a machine were responsible for catching on fabrics and violently pulling on the fabric, tearing internal baffles and other things. The agitatorless machines do not do this. While fairly forcefull, they do not catch on things. I am probably being too cautious on the delicate setting, but hate to take a chance with my bags. A light soap, Woolite or Down Wash, should be used to wash down, never any type of detergent (though soap will act as a detergent after 1000-2000 washings.) While down is safe from reasonable heat, the shell is not. Mechanical damage, chemical damage, and heat are the three main items to control while washing your bag.
I have a Whirlpool, about 3-4 years old thse days, I guess. I have been washing my bags every 7-14 days of use with no harm done to the bags. On return from weekend trips, I will often throw them through the dryer to make sure they are dry, and reactivate any remaining Down Proof in the down.