I have the same issue. Whenever I hold anything in my hands they immediately begin to sweat like crazy, no matter what. Honestly the best thing I've found to use was any mouse you can get a hold of that has some sort of textured grip, and by textured, I mean really fine, almost like some sort of sandpaper. It doesn't stop the sweating, but it mitigates your hand slipping off the mouse (which I'm assuming is why you want to stop the sweating). The Logitech G9 used to come with a second grip that was perfect for that, but sadly they don't sell those anymore. I'd suggest trying to find a mouse that has a similar texture style.