Total waste of time and effort.
A little wick or one powered by the feeble current of a USB cannot possibly add significantly (probably not even measurably) to the humidity in a cockpit under any circumstances, and certainly not with aircon on. Remember the refresh rates for cabin air?
Your knowledge of basic physics should tell you this idea is pure pie-in-the-sky woo-woo.
Drink the water if you feel dehydrated!