Not a bad idea at all! That's how I re-purposed the down from a sleeping bag and a jacket. They were already clean, so I just soaked them in the sink, then cut open one section at a time and gently scooped out the soggy down into a colander. I was able to salvage every bit of down without it flying around. (I also salvaged the 2-way zippers.) Then I divided the wet down into equal-looking little piles and re-used it while still wet. So much easier than drying & packaging it!
Be careful not to squeeze wet down! You don't want to break its loft-ability!
I prefer to harvest the down when I'm ready to use it, instead of trying to dry and package it to use later. It's easy to insert approximately equal blobs of wet down into the new UQ channels, then sew up the openings, then either tumble-dry it on the lowest setting or air-dry outside. No loose fluff to chase around the house, and when it's dry you have a new, clean down-filled UQ ready to go.
This has worked well for me, but I'd like to know how other folks recover and re-use down from jackets, sleeping bags, etc.