Good suggestion (as always) It is getting harder to find pipe-cleaners, so stuff like this is important.
Another Idea is to get wooden matches, , also have used rounded toothpicks and also for cleaning rotary switches. I have used copy paper and rolled it up and used it for cleaning small holes such as clock bearing sleeves. Paper is an abrasive and could also be used for relay contacts.
Your suggestion of those brushes could also be used for cleaning hard to get at places, like solder rosin on turrets, solder posts, cleaning dust around parts on circuit cards. A little rubbing alcohol added should be safer than most solvents, wouldn't hurt. But I would imagine even a little brass polish might remove tarnish on the pin sockets using the brush Idea.
Thanks for your Idea.
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