while i didnt actually put my bowl in the freezer i did do something similar. When i smoke in my house i blow the smoke out the window, and this winter while i was smoking i would put a packed bowl on the ledge of the window, this would cool my bowl down before smoking, and it did help to cool my hits, though only for about 2-3 before it was warm again, so it worked, but not for very long. And its been said before and ill say it again, but the warm water bong is the best trick, i dont know how it works, but it does, couldnt tell i had smoke in me.