thats just spraying the water on him. some like it some dont...mine doesnt...just test it out rather than soaking him and having him run away when u pull the bottle out.
Some people put there chameleon in the shower, this may cause extra stress. I just take mine outside, put em' on his plant and spray him with my pressure pump/mister, you can get from walmart 8$ He seems to like it.
I usually fill it with hot water and by the time it comes out in a mist its warm...