it is not a problem to directly mist your chameleon. if they open their mouth up to gape at you in an angry display, do not spray in their mouth as they could inhale the water. you also dont need to directly mist your chameleon, but you can as you are misting the foliage in the enclosure. a lot of cham owners will also put their chams in the shower once a week or a couple times a month on a plant, direct the showerhead towards the wall so that the spray bounces off the wall and then onto your cham using warm water for enjoyment as many chams like this. like you said, they get rained on in the wild! doing this as well as misting directly are also tricks for getting a dehydrated chameleon to drink!