Aluminum is a terrific conductor of heat. While not instantaneous it is amazing how quickly setting a frozen package on something aluminum speeds up the defrosting. Frozen package defrosts better the more surface in contact with aluminum. I have an aluminum frying pan - if small enough the package goes inside (and in the turned off oven so Domino and Mr Poe cannot get at it!) If larger, I flip the pan upside down and set the packed on the upended bottom.