They have now here in the Warehouse yarn which one can felt in the washing machine. Of course I had to try it out, I couldn't resist ;)
the finished slippers
the next pair is already almost finished knitting
thats how it shrinks
The next time I will take a photo of the slippers fresh from the washing machine. I was shocked first, because it looked so small. But they stretch nicely over shoe lasts, which gives them the nice shape.