I've seen chamber-cleaning tools for shotguns and rifles that are basically a section of cable with a handle on one end and a ferrule- appropriately threaded- on the other. Other day the idea occurred "Hey, why spend fifteen bucks when I can spend five or six AND a couple of hours time making my own?" So:
End of the cable as-bought
The press and all is not necessary; you can easily thread this by hand as long as you have some way to hold the tubing. Just make sure you thread deeply enough that a brush or jag can screw all the way in.
Update: for something with a large chamber, brushes for black powder rifles can be just the thing; say, a .50 or .54-caliber size. I think most of those are threaded
The stripped end of the cable fits loosely into the hole
Ideally you'd be able to crimp the tubing onto the cable, but I don't have and couldn't figure out a good way to do that, so I went the easy way: JB Weld. Clean the inside of the tube and the bare cable with brake cleaner, let dry, then mix the JB up. Put some in the tube, more on the cable, insert cable. Wipe the excess off and make sure you didn't put so much in that it gets into the threaded end. Also, do not glue the threaded end to the cable(no, I did not. For once.) I clamped the cable in a vise so this end was vertical, made sure the tubing was centered, and left it to cure.
Here it is today with a brush threaded on
Just to try, I chucked the other end in a cordless drill and tried spinning it that way as well as working it by hand, and it works nicely.
The two feet of cable was less than a buck, the tubing about four. If you don't have one, you'll need a 8x32 tap, or whatever size you need(shotgun brushes have 5/16x27 thread; of course, you can get an adapter to fit them to 8x32 threaded rods), and the JB Weld was about four dollars(and has many uses). If you use 6" of cable that's enough stuff to make four of these and have tubing and JB left over, and if you're careful with it the tap will last a long time.
You could drill a piece of dowel for a handle and glue the cable in, or- if you get really deluxe- get a piece of hex stock and drill it so you've got a end that'll fit right into a cordless driver.
Thus ends the presentation; go thou, and make a mess.
By the way, it being cleaning-related, Evyl has some Otis cleaning stuff to try out.
*Unless I've overlooked somewhere, of course; could happen.