I have a couple of CVA's
A really old .45 flintlock, and a blued .50 hawken. I clean 'em both the same way:
I use water as hot as I can get .... it dries really fast .....
I remove the barrel from the stock, an the lock from the barrel.
I put the breech end into a 5 quart icecream pail of hot soapy water.
I put a patch (I use mattress ticking) on the jag, run it down and rapidly work it back and forth toward the muzzle ..... essentially pumping water up the bore..... until the jag comes out, usually followed by a little water.
I run the Nylon bore brush down the bore once.
Repeat the water pump thing a couple times with clean patches.
I drain the bore.
I dry the bore with more patches. The hot water evaporates really fast.
Once the patches come out dry, I run a bore butter patch down on the jag.... or a patch with a bit of Rem oil followed by a couple of dry patches....
and scrub, dry and oil the lock, outside of the barrel and brass furniture.
Re-assemble.
I shoot only real BP in my guns, and don't shoot plastic sabots either, so there's no need for any solvents other than hot soapy water. I use a bit of Crisco on the patches for the round ball in the flintlock. The Hornady 385 gr Plainsman bullets for the Hawken come prelubed .... no rust problems for me.