X2... I would think it might work if the heat source was not too hot. Different people in different climates, different coop set-ups, different cookie tin heater designs, different wattages of light bulbs...all way too many factors to sift through to know if your setup is going to work or melt your bucket and/or burn your coop down....
It's a trial and error thing. No 'one size fits all' thing with poultry management.