I found a great breech plug and thread cleaner brush at my local NAPA auto parts store. $5.00
It's made for cleaning battery terminals, so you'll have a multi-purpose tool.



It works great on my Omega.

I have one that is very similar. I dunno, the bristles seem a little hard for me. I'd rather use a softer metal.

Yeah 7.62NATO,
The bristles are stiff. So far I have found any problems. I guess if someone feels the steel in their breech isn't harder than the brush, they shouldn't use it.

I assume since the bristles are made of a steel designed to clear lead terminals, they can't be tempered very hard. - BUT- It's always better to err on the side of caution.

Might not want to use that hard of brushes on the inside of the barrel, but doubt it would hurt the breechplug much.