Ok, ok... keep it calm here.

If you use a disinfectant on anything while the animal is still around, it would be pretty much the same as if you added the stuff to your drinking water or to a mister you used on yourself in summer. Inhaling the fumes, no matter how diluted, can damage the windpipe and lung tissue to varying degrees. In humans, it can do anything from give you a really bad cough, sorethroat, and headache, to bad lung damage if used continuously. With a snake, that is more sensitive to airborne particles than humans are, it can give them Respiratory Infections (RI) and damage the tissues of their air passages.

That's what can happen if you mist with a disinfectant. And the more you do it, the more damage you can cause the snake and yourself (because you breath it in as well).
When misting for humidity, all you need is regular water.