John Weston wrote:
Find a close fitting, heavy, ball and drop it down from the top.

Preferably on the end of a rope, otherwise when it hits he hearth it
goes bouncing across the room :-) - or gets stuck on the way down :-)

Yes, a good idea, the rope, in case of it getting stuck. And maybe not
to close fitting either. Actually combine Owain's idea of cat sprayed
stiff with hairspray with the ball and come up with a ball-brush. Still
has me on the roof though, which I'm not to keen on!

Eddy.