Instead of attaching the suede soles as recommended by the pattern, I painted the bottom of the slippers with this lovely-toxic-smelling plastic paint. (Suggested by the lovely ladies over at the KR Forum.)

I used “PlastiDip” which is for the plastic handles of tools. Available at some hardware stores (let your fingers do the walking – call ahead). I just sort of blobbed it on and painted it around. The felted fabric really absorbed it so I was generous… in hindsight it may have been better to let the fabric absorb a small amount as a base, let it dry, and then do a second coat.