you might try finding insulating materials to stuff in your attic ( any
excess could be stuffed up Raid's "grand canyon". Also you might
attack a pinhole orafice ( trying different sizes till you get good
cooling with a minium af water ) to a hose and put it on the suction
side of a fan, it takes alot of heat energy to change liquid water to
gaseous water, much more than you might think. Or you might use a
wetted cloth, but it would reduce airflow and might be hard to keep
properly wetted. There are commercial units like for industrial spaces
that that make great claims. good luck