Redneck tip of the day:
We use bread wrapper twist ties to clean hard to reach holes and places in firearms. The wire is lite and easy to bend yet protected with the vinyl outer wrap. Works exceptionally well to clean the plug hole where your 209 primer shoots the fire down through the breach of an In-line muzzle loader.

Torch files used to clean the ends of cutting torches also work really well to clean fouled breach plugs!