Flushing the rad and associated pipes. If you remove the big pipe on the thermostat housing (mine is the later plastic type) you will find that one of those "Hoselock" connectors is a reasonable fit inside the hose. A quick nip up with a jubilee clip makes it a water tight fit and hey presto, an easy way to power flush the rad. Obviously you need to take off the other hose (in the engine bay) so the water can exit. Oh, and make sure the "Hoselock" fitting is NOT one of the ones with the shut off valve built in
Whilst you are doing this I strongly recommend you use the hose to check and flush ALL the thin hoses in the engine bay, especially the bleed ring and the 3 (or is it 4) "T" connectors. That is an area where blockages are not uncommon.