Not only does this work, but it is also the only way to use a temple on a narrow project.
Because I don't have a lot of yarn, I weave quite narrow strips--3 to 5 inches usually. There are no temples available that are this narrow.
The images below show how to use some regular elastic and a couple of metal paper clamps. The trick is in the fastening. The fastening mechanism has to be kept out of the way of the beater. Once I had the elastics tied to the pole of a lamp on one side and a chair on the other. I've moved beyond that now with these two "quick clamps" available in most hardware stores.
Just make sure you get the "pull" on each side as even as possible.