That's just what I intend to do sunshineband.
That was the reason I asked about not having enough room in my compost bins. I have a hexagonal bin and I cut out two halves of expanded polystyrene, wrapped black plastic around them and placed them on top of the bin's contents. My word, what a different set of beasties munching away when I gently move the foam to 'ave a shufti'!
Cheers, Tony.