Glues that are used to hold HS's on are stronger at higher temperatures than at lower temperatures.  Freezing them makes the glue brittle, & easy to break.
As for getting the card moist, it's possible it will develop a slight layer of condensation if you pull it out in a humid environment.  My GF2 GTS had no problems whatsoever with the process, though.
Up to you, but I'd use the freezer.
Viper GTS