@RWTS in regard to the vinyl skins for NST I had ran into them on Amazon when I first got my ST in September, but I haven't found them again. What is still available is
this silicone sleeve thing that completely covers the ST right up to the screen. The link is for Ebay but it's on Amazon too. Depending on how steady your hand is and how high your patience you can make your own vinyl skin as sheets of the stuff are sold in tubes for like $20-25 I've found them in Walmart, craft stores, and also automotive stores
I'd try cornstarch too but it might work just like the talc.
It sucks the Armour All didn't work for you as it was the least messy and easiest to apply in my case. I do have to apply regularly when it's warm or I've used it a lot.