Encore breech plug...
That's the same as used on the T/C Omega.
The gang over on modernmuzzleloader all use a hand-turned 1/8" drill bit to clean out the carbon from inside the primer end of the plug. That, plus a nipple pick or a "teeny tiny" drill bit for the other end of the plug will get it clean.
At the range, use the drill bit after every 5 shots, along with the nipple pick.
And don't forget the breech plugs should be "finger tight" only -- not really snugged up. Most hi-volume inline shooters unseat then lightly snug the plug every 10 rounds or so (I do it after every 5, whenever I clean the plug, as it takes no time at all). Do this, and you will never get a stuck plug -- as long as you've greased the plug and threads correctly (or used teflon tape like some shooters do).
Tight groups.
Old No7