Hello, I sat down outside on a concrete ledge and took out my Surface Pro to do some homework. I didn't realize that by touching the ledge as I sat down, I got some while chalky substance on my palm and fingers. I then used that hand to touch my Surface, and afterward realized that I had transferred smudges of it onto the back side of the tablet as well as the keyboard. I tried to rub it off with toilet paper and water; I managed to mostly get it off the metal parts (though if you look closely a white tint is still pretty apparent), and it barely comes off the palm rest and keys of the touch cover. Fortunately, the small amount that transferred from the keyboard to the screen when I shut the tablet did come off with water. I work in a lab and have access to common solvents... how should I go about cleaning the Surface? I was thinking of trying ethanol or isopropanol but I'm afraid of washing off the paint. Any advice would be appreciated. Thanks!