I sew them also. Just stack them up on the needle until you have it like you want it, push the needle through several times, and knot it off. I think it's much easier, you can get them much more centered, and it can't be easily destroyed.
I have a friend that uses the elastic on her little girl's korkers. Everytime I see her wearing one, the little girl is pulling them out. I can't imagine all of that work being destroyed.