A little clarification in how I personally clean my longrifles. First thing I do is remove the lock for cleaning. Then I put a toothpick or twig in the touch hole. Then I pour what I guess to be about 2" of my cleaning fluid (can be water but usually I use some MAP) down the barrel and stand the rifle up so the fluid can soak in the bottom of the barrel. Then I clean and oil my lock.
At this point I wet a patch and start sliding it down the barrel. Since I have a toothpick or twig blocking the vent I start to feel back pressure. I typically push until I feel it's enough pressure (gets harder to push farther); point the vent away from anything I don't want to stain black; and quickly pluck the toothpick out ramming the ramrod down forcefully. This will push about a 6-foot stream of ugly black junk (fouling) out of the vent. Then I'll go ahead with wet patches until they come back clean; fun a dry patch down to dry it off; and finally put a little on a patch and run that down and up a couple of times to put a slight coat of oil on it. This has worked perfectly for me for the past 10-years and YES it will clean out those patent breeches perfectly without a separate brush. I used it on a Traditions longrifle originally and it has a patent breech on it. Never had a trouble with breech being clogged as long as I cleaned my rifle every day that I shot it.
By the way, that caution about pointing the vent away from anything you don't want stained black is very important. You'll be amazed how much totally black crud comes flying out the vent and how fat it reaches. I stained a tent that way the first time I did it....oops!