I have knit up two oversized pairs of wool clogs and a pair of mittens. They look like clown accoutrements, and are not considered finished objects, because they need to be felted down to proper size!
The very best washing machine for this is one I will not see again until August, so if I want warm fingers and toes (and I do!) I'm going to have to attempt this in my washing machine of considerably less power and magnificence.
Meanwhile, an addendum from last time:
That worked out well, I think.