This was 11+ when my brother Paul and I both redpointed it on my birthday in the early 90s. It's now the hardest rated climb I've done, but I think redpointing Kligfield's Follies was subjectively the hardest climb I've redpointed.
There's a flake at the crux (out of the picture to the right--the roof is much bigger than the photo shows it to be) that you can grab with your toes. When I did it I had at least one bare foot to grab that flake. The bare feet suck when you get to the foot jams depicted in the photo.
Kevin Bein used those red rubber child low cut galoshes that he bought specially for this climb. He apparently got some strange looks in the store when he explained that the galoshes were for himself.
It's been done, perhaps many times, with climbing shoes, and perhaps a very soft slipper would allow you to grip that flake as well as with bare feet.