congrats on a fine lookin smokepole!
ya prolly don't have the tooling or wanna do what i do with every new investarms gun - pull the breech plug and lather the threads with anti-seize lube, dittos for the bolster/snail. that'll insure easy removal later on, by inhibiting the migration of bp residue that gets into everything sooner than later. but no big deal. at the very least, you WILL wanna clean out the proofing residue in the anti chamber. i don't think the bolster is on for proofing, that should be reasonably clean, but wouldn't hurt to clean that as well. this is what's in yer breech and ante-chamber (aka "patent breech") before yer first shot ...
the investarms ante-chamber is smaller than the bore ...
a .32 caliber (or so) nylon or bronze brush with some moose milk (or whatever) and a thin patch will clean out the patent breech, then a .50 jag and patch for the bore. yer good to go. a bit of gun oil on patches for the brush and jag will preserve the barrel metal. before shooting, i run a dry patch or two to clear out most of the oil.
another mod i make is to take the investarms ram rod and grind down the bell that's on the ball ramming end - grind it flush to the rod. this allows the ramming end to fit into the stock. then you can screw in the jag to the other end. both are ready to do their jobs, and the ram rod will not have to be flipped around every time you load a patched ball - it'll be all up and down, rather than up-flip-down.
also, both of the brass ferrules will be far more reliable if you drill a 1/16" hole into each, drive in a nail (brass or soft iron/steel), nip it close, then peen and file the brad ends flush to the ferrules. there, now they ain't pulling out and ruining yer range or hunt trip. it's good to make up an extra ramrod, too. 3/8" oak dowel works well, despite what some folks say. get the ferrules online.
enjoy!