"My only proper chain cleaning device broke on its first use twelve years ago. I did briefly try using a couple of nail rushes clamped together around the chain but it quickly results in a pair of nailbrushes gummed up with dark brown chaingunk and no appreciable reduction thereof on the chain itself."
Are you me? :)
I got a chain bath free with a can of muc-off, which broke on the first use. I then also moved to two Tesco nail brushes held together, and liberally covered in muc-off chain cleaner - the brushes don't go black, but if you don't clean them properly the muc off causes the nail brushes to disintegrate.
I tend to take my rear wheel off, clean the casette with muc-off and an old toothbrush, then use the nailbrush & muc-off technique for the chain, then muc-off and toothbrush on the jockey wheels. I think I'm single-handedly keeping muc-off in business.
People at work swear by this: http://www.wiggle.co.uk/park-tool-cyclone-chain-scrubber-cm-52
I've yet to try the baby wipe (I've also heard flash wipes work well too) technique, which is probably just as environmentally unfriendly as using half a can of muc-off - I'll give it a whirl this weekend, since my chain is starting to look decidedly gummy.