How about this theory. The hot water causes the freezer to run its compressor sooner.
This may happen but, in a normal freezer, the action of the compressor is meaningless.
My feezer is 70% full, with probably 30kg of stuff in it. This stuff is mostly at -22C (I have a thermometer), and so, this mass is what cools new things added to the freezer, fast.
(Why -22C instead of -18C? Salt water fish is in there, and I also want a little headroom.)
This may happen but, in a normal freezer, the action of the compressor is meaningless.
My feezer is 70% full, with probably 30kg of stuff in it. This stuff is mostly at -22C (I have a thermometer), and so, this mass is what cools new things added to the freezer, fast.
(Why -22C instead of -18C? Salt water fish is in there, and I also want a little headroom.)