I always see those airfoils and think "eww".But I don't see any reason you couldn't make a cardboard wing with a symmetrical airfoil.Chuck's cardboard techniques are quite innovative, but sometimes it goes to the extreme. The airfoils are just "bad" for any kind of stunt flying. Either just build a conventional wing, or use a bit of balsa for ribs and spars and go symmetrical. If you strip off the inside ply of the cardboard where it has to go around the wing(just leave the outside ply and the corrugations) it can be bent around a pretty tight curve with just a few ribs.