I used to felt in my washing machine, but now I only felt by hand. What prompted this change was the death of my old washing machine. I replaced it with a modern washer with all the bells and whistles. It's one big computer. It's constantly sensing the wash. I can no longer fill it up with super-hot water and let it agitate until my knitting is a firm piece of boiled wool. So now I felt by hand. It takes longer. But it does allow more control over the felting process,