Spiralling, you will need to sit into the stance and lean the upper body slightly forward (just enough to let your shoulders end up at 45degrees to the hip/wall. Amongst other things this is an aid to help you isolate the turn of the upper body left & right without moving the hips. Once you can do it, repeat the same feel away from the wall.
Huh, actually, I'm not clear on the spiral bit but the butt on the wall thing I can do two different ways - one clearly wrong and the other is less wrong (might even be partly right). Simply tilting the hips left and right one is able to keep the knees over the toes and the butt against the wall but the lower back gets all wierd. Actually turning at the waist/lower back while being mindful of keeping the spine mostly straight is closer to what I think is right.
I'd caution that the butt check is only good for the hips rotating horizontally (forward and back). Checks are great but just because one passes the check does not mean things are going right! Check fail is fail - check pass maybe fail, too. So many ways to fail.