It's beneficial to get them wet too, although some people might possibly disagree. If they can get water into their eyes it helps them flush out any dirt in them, which is obviously a good thing. And I personally think they enjoy getting their skin wet every once in a while, and it probably doesn't hurt in keeping their skin hydrated.
I do the exact same thing as Carol suggested, I spray them with hot water and it mists out warmish and they usually love it. With cold water they generally run away from it! Also, it's important to note the intensity of the mist. If it's a fine, gentle mist then it's less likely to spook the cham, but if the jet is much stronger they may run from it regardless. In that case, you might want to spray them indirectly.