Easy Gunk Removal
Ok, here's the shots. Promise not to puke.
First, here's the parts you will need.
I use the bungee cord to keep the wood dowel and breech washer slammed into the top of the chamber. There is a metal tab the I initially thought was going to be enough when rotated like the bolt, but that leaked, hence the bungee cord. The dowel is drilled just a tick so that the pressure is on the washer and not the brass tube.
Next a close up of the top:
You can see how I cut the washer so that the liquid can pass into the barrel and the gases can escape. I notched the washer a little better in version 1.3 so that it drops into the barrel a little better. It fits snugly into the clear plastic, which allows you to see the reaction bubbles arising.
Next a close up of the breech faucet washer.
Here you can see the glob of solder I put around the base of the rod assembly. I used a brass tube for the outer assembly knowing I would be able to create a good solder joint then inserted a brass rod down the center for stiffness. You can also see that less krud was coming off near the back end versus the brass rod in the middle.
What you are removing looks like this:
Initially, version 1 just used a 12 volt car battery that's been in the garage for a while. I doubt it's up to snuff. My final version will rely on a HO gauge train transformer.
I only ran the setup for 15 or 20 minutes pausing to wipe foam away and refill with the water, vinegar, ammonia mixture (2part water, 1part ammonia, 1 part vinegar).
Then took the cleaning kit out and the wipes were coming out brown for a good while. Started with a brush, just to shake loose remaining grime, then your usual cleaning process.
What more can I say? If you are into old battle rifles, this setup would seem to be a must.
KKKKFL
Of course when I folded the bayo down The groups shifted low and to the left and opened up a bit. 
