I just put grab the mouse out of the freezer, let it be in room temp for atleast 10 min or so, I warm up some water, (not boiling) and I put said mouse in a zip block bag and put the littler sucker in some warm/hot water for about 5 minutes. By the time its done you can see all the blood inside the pinky, its also pretty warm to my touch. ( I have pretty sensative fingers) I put the sucker in the feeding cage, and not less than 1 second later she snags it without a second thought.
I find this method the easiest and quickest.