My brother's house in Perth, Australia has an antique air conditioning system in the roof space that works in exactly this principle. 4 blankets that wick up water and have air drawn through them and into the house by a fan. It's in disuse now but I understand they were common and quite effective in the day.

They're usually called "swamp coolers" and are very effective iff you have very low ambient humidity. Utterly useless in humid climates.