I use finger cots or plastic wrap with a rubber band around it. I don't know if the sabot would be a good idea. I wouldn't use anything that could even remotely have a chance of building pressure in the barrel!!!

With elect. tape, finger cots and plastic wrap, the hot gas from the muzzle burns these before any pressure can build up. The sabot could somehow get lodged in the barrel and act like it was pluged with mud or something. Could end up being a really bad day for you!!!