What works the best to clean breech plugs?

HOT soapy water and or breakleen( you can get it at the auot parts store).

Let the plug soak for a halfhour or so and everything should come off from it without to much problem

When I clean the breech plugs, I take them out of the inline rifle and to the kitchen sink. There I have a little dishwater made up (hot water works best). I have a nylon brush and I can soak that plug in that hot water and then scrub it spotless in a matter of moments.

After that I pour some isopropyl alcohol through it and then work it over good with Q-tips to make sure I have not missed anything. They look as good as brand new when I am done with them.

Good ol WD-40 with using the straw to blow through the hole in the breech works for me. I follow that up with a soak in Knight cleaner and hose down with Iso alcohol to make sure it's all dry. Then lube it back up with grease and put back in.

Betcha one of those little ultrasonic jewelry cleaners would work like a champ. She'll never miss it.

I let it sit in Hot soapy water for 15 mins then I scrub off all the junk after thatI use90% alcohol and do some more scrubbing (if I miss any), dry it and I'm finish.

After you have run an open paper clip inside the plug - then used a sewing needle to make sure the flashole is open, follow these steps. Inside of the plug should see your hottest tap water while holding the plug with a pair of pliers -- thenautomotove brake cleaner spray -- using the long, red/yellow straw-looking adapter that attaches to thefinger nozzle. Keep away from your body when spraying - do over a laundry tub or driveway -- cuz' it may shoot backwards and sideways too. It's important touse frequent short thrusts in there.

The outside should be done first. It should see Q-tips and those stiff, wiry pipe cleaners dampened in solvent for the 209 primer area -- then any household spray like 409, Simple Green, Fantastik... etc.. with a toothbrush for scrubbing the outside of the plug.

Whendone inside& out, try that sewing needle one more time - to make sure that tiny hole is open. I then leave my breechplug flashhole-up overnight on a shelf - the cleaned/oiled ML nearby standing up with muzzle-down and a foldedpaper towel under the muzzle to catch oil run-off. Next day, I'll install the plug - then place the ML in the gun safe muzzle-up.

I am meticulous with my guns. I probably 'over-clean' them. Takes me a long time to clean a gun - because I am so thorough.

Thompson Center Arms -- Triple Se7en Powder -- Buffalo Bullet Co.

I use Windex with vinegar mixed 50/50 with water.I putit in a spray bottle and just spray it on the breech plug. Most of the crud on the breech plug is almost instantly washed away. Use a toothbrush on the threads to finish the job. I run a nipple pick through the flash hole and use pipe cleaners in the hole under the recess for the 209 primer in the CVA. Elapsed timetwo minutes. This stuff works fast.

Being curious, I tried your Windex Multi-Task with vinegaron a dirty plug with anti-seize residue. Even tried it full strength. Then tried full strength Simple Green -- then tried full strength Pine-Sol/Murphys.

If I didn't have a rag or toothbrush nearby,a littleof the exterior residue was still remaining - despite all those cleaners I tried. The best alternative I found was Brake Cleaner/Gummout spray. But I refuse to stink-up my laundry room & basementwith that stuff. I only useabrasive, toxic chemicals outdoors - only squirting the inside of the breechplug with the nozzle extention- then blow it out with my garage air compressor. The whole exterior of my plugs gets cleaned with a toothbrush first indoors- otherwise plenty of greae/residue remains trying any singular home-cleaner spray. I won't waste the Gummoutspray whilecleaning the exterior. One can of that stuff lasts mearound one-hundred plugs - if I only shoot the plug's interior with it.