The problem Christine is having, again, is either or a combination of:
1) The bag needs more laundering because there is an excess of body oils in it.
2) The bag was incorrectly laundered at some point, or, washed in a machine with enough detergent residue to harm the down.
No, down does not have actual lanolin in it. The oils change from species to species, but it is loosly bonded to the down. I describe them as lanolin like. They are bound as part of the protiens making up down feathers. Similar in nature to lanolin bonded to wool. Detergent has an affinity for oils, ie, it attracts oils, and, it attracts water. So, the oils come out of the feathers. The same will happen to wool. It can get stripped of it's lanolin by strong detergents, hence Woolite is used. What is left gets brittle, less resilient, wool or down. In use, down will loose loft and fibers will break…leading to clumping, balling and dusting. IFF you cannot separate a clump, this is likely the cause. Usually a plume is many fibers. Extreme wear can cause some to break off. I refer to this as degraded. But the difference is the fibers on good but used down are still flexible enough to promote lofting. With oil striped fibers, they won't, they just clump up again, usually within a couple nights of use.
Since Christine says she gets clumping after a couple weeks, I would *guess* this is simply damaged fibers, perhaps some oil stripped fibers, but the majority of the down has some flexibility, ergo, not badly striped. However she mentoned that she DID have the bag dry cleaned. I would guess her problems started about 2 weeks after it was dry cleaned. I am guessing again, but if she continues to use the bag, she will need to launder it carefully in the future to preserve any oils that are left. If the problem continues to get worse, she will need to have the bag restuffed. There is no treatment to replace the oil IN the down once it has been stripped away that I am aware of. There might be, though. Hence my encouragement to call WM. Tell them what is happening. Tell them a fairly accurate time line. It could be they will simply say to wash it more. Do this first. No sense wasting their time if you can solve the problem with a simple good washing. If you have the same problem after a good washing…well, it must be oil stripped down. This will need restuffing.
Compression does NOT hurt down. About 3 years ago I did a survey comparing compression, storage methodes with the effects on performance (measured loft.) After compressing a bag, shaking it out and loostening the fill up, after laying it out for an hour, worked as well as carrying a loose bag. The range went from xxxsmall to just loose in the bottom of a pack. There was NO difference. A member also reported that emergency blankets were super compressed by vacuming air from them (military.) Years later these were used, just shaken out a few times to loosen the down.
Down is as much as 98% air. Every fiber is resiliant and springy. By hand, you cannot get a bag compressed enough to damage the fibers. Even 50:1 or 70:1 compressions by volume will not cause enough pressure on the down to cause permanent damage. You will need to shake it out, though. I have been on 2 month trips while compressing my bag down to 40:1. Over half that time, it was in my pack, hiking 10-14 hours per day. Compression does not damage good down permanently. That said, my bags are hung in my gear closet. Actually, the same bag I had used on that trip is fine and still certainly usable. Initially I was surprised at the results. But, having put it in practice…it works.
