Moleskin willdefinitely wear out, but it'll take more shots to wear outthan you think. Besidesmoleskin is cheap and easy to replace.
If you want something that's more durable but does the same thing, use the furry side of velcro. Or get some thin, pliableleather and glue it (Barge cement) around the rest's support finger and on the strike plate.
You already know the arrow and rest squeak when rubbed together, so you want to do anything possibleto put some different material between the rest and arrow. I don't think your idea of putting a felt washer behind the rest will do much, because that's not where the squeak is coming from.