Set Square wrote:
In an earlier thread, I described a device which I had made to enable a
radiator to be drained prior to removal by pumping air in through the bleed
hole - thus pushing the contents up into the F&E tank (in a vented system
only, of course) rather than spilling it all over the carpet.

Alternatively, if you've got a wet/dry cleaner, you can switch it into
wet mode, turn it on, then loosen the nuts to allow water to flow out
and be instantly sucked sideways.