I use a wire to clean out the flash hole. I run it thru the breech plug, a couple of times, wipe off any residue that sticks to the wire, and reinsert. I do it from both ends. I don't know what gauge wire it is.
I've been using the wire tie that comes on loaves of bread. Get one of those ties, straighten it out, strip off the paper or plastic coating from one end, leave the paper or plastic on the opposite end (it helps you hold the wire), and push it thru, first from one end then from the opposite end.
Been using it to clean the breech plug on my Sidekicks, Huntsman, both old (45Cal), and new (50Cal) types, and Omegas. Works for all of them.