Fine wood and water don't mix ... water can and will raise the grain ... why take a chance with what will, in the long run, be a meaningless shortcut ?? ... put a container of water (any water will do, but use distilled if it makes you feel good) into the humidor and close the lid ... leave it undisturbed for a week or maybe two ... put your calibrated hygrometer in and check it out ... when it's stable at 70, take the water out, put your cigars in and you'll have years of happy motoring ahead ...
Of course, no one can say you WILL raise the grain and ruin the wood by wiping with water (and if you do choose this course, DO use distilled water) ... it's just that no one can say you WON'T raise the grain either ... hell, you COULD get away with pouring a cup of water in, closing the lid and shaking the unit well, then dumping out the excess water ... I know guys who've done that too ... but it's more than a little risky ...
It's YOUR humidor .. do what you think best ... but, having worked for a number of years in the wood furniture business at one time in my life, I know what I'd do if it were mine ...