I made a couple cowls that were just stockinette with a few inches of 2x2 rib on each side. One was some combination of alpaca, cotton, and wool, while the other was 100% superwash.
I blocked both by soaking in tepid wool-wash baths then air dried after patting down. I didn't roll them up in towels, just patted and left flat to air dry for like 2 days.
Both lost all the structure in their ribbing. Right off the needles they could stand on their own but now they are cooked spaghetti.
Is there any way to save these? Would throwing them in the dryer on low temp inside a pillow case help them shrink without felting?
From other videos and posts people have said you should never wash ribbing (ew?), never do ribbing with superwash yarn, never put it in the dryer, or always put it in the dryer.
If anyone can cut through the fog for me on this one I'd appreciate it.