I would love if anyone wanted to send me their selvages. I'd gladly pay for postage, trade for fabric or make you something.
Washed or unwashed fabric is fine. I like to see a little of the fabric print, so I usually cut mine 1.25" to 1.5" wide. You don't have to measure or anything. And any length is usable.
They're very fun to play with if you want to give it a try.