I seen many guys do the dry brush thing and knock the powder out. It works for some and does get a lot of the fouling out. I swab 3 times between each shot. 1 wet (TC 13), 1 dry, 1 lube (wonderlube).
Here is my reasoning: My barrel is clean and lubed when I load the first shot. I want every shot after that to be a consistent as possible with the first shot.
1. I never have a mess after numerous shots when it's time to clean it.
2. I can push the projectile from muzzle to breech with a finger tip ( PB's in a Lyman Great plains)
3. If I take multiple shots and don't clean it that night, the barrel does not rust etc. because I lubed it when I loaded the last shot.
4. Instead of shooting the gun to unload it, I simply walk out in the garage and with about 30lbs of air from the compressor it send the bullet out unscathed. I then use a patch worm if needed to loosen the main charge powder. It may take more pressure to get a roundball and patch out. The absence of any fouling make this a very easy process.
In your case (loading without powder)........yes, I have done that too. It eliminates the need to drill and pull the projectile. A lil' air and out it comes.
My methods are my own and work for me. Many have asked, some tried, some liked and disliked. I can only vouch for my personal results and of the results I have witnessed from other using these methods.
( That is my new personal disclaimer to discourage some who are ready to jump all over friendly advice)
Flintlocks have made me a much better shot and have taught me something else...........patience. I really needed the latter!! Good Luck and keep on Smokin!!