On Tuesday of this week, we got some derotational straps/mummy leg wraps for Lo-gone-oh. They make these things one-size-fits-all, needless to say, they were huge. We put the "belt" around his waist and wrapped and wrapped his legs like we were about to mummify him. He stood up and walked and... lo and behold his feet were being turned forward.
So now he gets to wear these for a few hours every day. His PT still wants him to work without them as well, to strengthen his muscles - but they give a great stretch in the right direction and he's not tripping over his toes!