GB wrote:

ARW wrote:

it's a magnetic cleaner so full of the
crud that it has collected that it has split open.

I'm somewhat perplexed by that. The only one I have ever opened up has a
magnetic stick enclosed in plastic, and the central heating water swirls
round the outside of the magnet.
Pin-prick hole in the plastic, letting water into the magnet which has
rusted and expanded, splitting the rest of the plastic open?