I didn't say water isn't a good conductor. I said it's ridiculous to claim that "incidental saliva" is the reason why blowing on a cart works (when, in fact, it often DOESN'T work). That twists good science (water as conductor) into non-science (anecdotal "evidence").

Google's claim that his carts ONLY work when he blows on them is dubious, and the explanations in this thread are equally so.

And are you seriously comparing the heating effects of a puff of breath to a hair dryer?!

-- Z.