My cousin in Tamworth - in his younger married days - killed a swan and put it on the Rayburn (UK coal cooking/home heating range) for three days - he had to decant the water each day to get rid of the grease. He reckoned it was still greasy and gamey.

Ollie refused to eat the stuff. Not that she is a Royalist or anything. (all UK swans are the property of the Queen)