As a spinner and knitter, I feel I should point out that we have some apples and oranges being discussed here. The felting tendencies of these fibres depend on their physical structure, especially the scales on the shaft of the hairs themselves. These scales are what hook together with water, heat, soap and agitation to form the fulled or felted fabric of a ruined sweater. Cashmere has very few and very flat scales and thus tends not to felt as much as a coarser wool. Merino tends to be the least 'felty' of the wools for similar reasons. Allendubner, your Goodwill sweaters may be of a more scaley type of wool than merino, and thus may not be good indicators. I'm getting a new LG washer and dryer this week (if LG gets their inventory act together and finally coughs them up!) but I hadn't intended to clean my handknitted stuff in there. But you've given me the incentive to knit up a few test swatches and try!

I hate to tell you this, but washing is no guarantee that fabrics won't bleed later. I have no idea why, but even fabric from the same bolt might act differently. Just yesterday, I had a small scrap of RJR panel print to make a label for a quilt. Spritzed it a bit first with cold water to press first, and very soon, the reds ran. All the fabrics were rinsed in cold water before I used them, and nothing ran. So, I got another idential scrap, and rinsed it in cold water first, to check. No running. Huh? So I got another and spritzed it. No running. It was all from the same bolt. Hmmmm. I guess I will just use one that didn't run. Go figure. I'm left to wonder what will happen if the quilt itself ever gets washed. It would not be the first time I've had this happen. BlueBars

@elizabeth - for some other resources to check, have you seen this very long running thread on the W1 washers & T1 dryers? - https://www.houzz.com/discussions/5434365/miele-w1-t1-washer-dreyr#n=985 If you haven't seen it yet, it would be worth your while to check it out while waiting for further responses here. To see all the posts, remember to click on "see more comments" which you will find at top immediately after the original post and Houzz's "featured answer." Also, there is another thread here which is specifically about washing bedding (including king-size blankets and down comforters) in W-1 washers, which you can find here: https://www.houzz.com/discussions/5820932/miele-washer-and-dryer-w-1-t-1-capacity-king-duvet If you haven't visited automaticwasher.org, that's another place you might find helpful. Here's an example of a potentially helpful discussion from the washer enthusiasts who congregate there: https://www.automaticwasher.org/cgi-bin/TD/TD-VIEWTHREAD.cgi?83323 When I was looking at washers a couple of years ago, I ran across some youtube videos such as this one which shows a king size down duvet (aka comforter) being washed in a European W-1 model. This video was made before the W-1 line was released in the North American market but the capacities would be the same. The link, if you want it, is: https://www.youtube.com/watch?v=EGA0k0Z56FM FWIW, I also found similar videos for Bosch and Electrolux compact washer models.

"For future reference- if you have a wet/dry vac, you can often use it to suck a clog out of a discharge pipe." And you may not want to know what else you'll suck out of a sanitary sewer! I'm not very squeamish, but i'd prefer it flow away from me. If you want to save money get the pro quality snake from a rental place. It's not too hard to do. Most folks, understandably, are happy to pay the roto rooter guy.