Hmm.... the chain flail minesweeper thing is pretty awesome... but I've never seen one on a model. You could just make your own. A few coats of clear varnish applied to some necklace chain and a stick from your back yard ought to do it. adding some spikey balls to the ends of the chain be good as well.
You could probably do it with bits as well. Skaven monks have a morning star weapon option that would work (only 4 of that arm in my box tho, so you'd probably have to spend a fair bit of effort locating enough of these)