Anyone have experience with cornstarch slime? Does it cling to hair like flour, or does it clean up easily?

There are no cleanup problems I am aware of with cornstarch/cornflour.

There isn't any gluten in pure cornstarch, so it won't have the balls that flour creates in hair. If you want to be sure, check the label to make sure they didn't add something with gluten (wheat, barley, rye).

I can tell you from vast first-hand experience that a little water takes care of it very quickly.