I use a mixture of half rubbing alcohol and half distilled water on all screens with screen protection or not without issue. I'm a bit anal about dirty screens on any device(just ask the wife). I also use clean cloths that's not used on anything but LCD screens. Picked up a package of 5 micro fiber rags at wallymart for like 5 bux. A gallon of distilled water less than a buck and the rubbing alcohol is less than a buck a bottle. Get you a spray bottle fill it half and half and your ready. Been using this combo for years and all our screens in the house look brand new.
I've used invisible shields on many devices and you can use just about anything to clean them. I've used just water and a paper towel, cleaning solution for glasses and a microfiber cloth, windex and paper towel, etc. The shield is designed to take the chemicals in the cleaning products without diminishing the product. That is one of the reasons why they offer a lifetime warranty.
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