Wouldn't have anything to do with that. If anything, cleaning the guitar would make it smoother and more slippery. Think you just need to keep practicing that chord. Maybe angle your hand a little more. When I play it, I notice that the only part of my hand (other than my fingers) that touch the guitar is the part between my thumb and index finger. My palm isn't around the neck. If I do that, then my ring finger will slide back more. Also, if it helps visually, my middle finger on 6th sting G is kind of pointing at my left shoulder, not straight up and down the fret.
Try placing only your index and ring fingers to find the spot that is comfortable. Those are the 2 fingers that really determine the hand position. Once you get those, laying down your second and fourth fingers is easier. Pinky should be the last one you lay down. Once you find a comfortable position, just keep trying to get faster at going straight to it.