I don't know if you tried this or not, but when I thread elastic into a casing, I put a safety pin in the leading, kinda like a needle. Then you push the closed safety pin into the opening of the casing and work it through to the end. It is hard to put into words, but that is how I would do it. Not sure, but with an 8 inch opening, you should able to reach your hand in far enough to reach both ends of the casing to reach the safety pin and remove it at the other end after securing the ends of the elastic so the don't pull all the way through.
Last edited by nursie76; 02-03-2013 at 06:18 PM.