Well since we cant get the OMNICLEANZ here anymore ... homebrew something almost as good as follows .
You REALLY should avoid anything that contains the likes of ammonia, acetone, toluene or ethyl alcohol , as these are solvents and while great at disolving oil based fingerprints , they are also quite good at disolving oil based plastics and removing Uv and other coatings on your LCD/LED screen ( glass covered screens have less issues with your windex type stuff, But most of these things still leave a bit of residue behind , which will require buffing out anyway , and any oilphobic , uva , glareproofing ect coatings are at risk with chemical ,or physical friction, for this reason use minimal pressure while cleaning ) so, IMO better to have the safest option on hand to aviod potenial mistakes when in a jam) . I find the smaller atomizing bottles desgined for lens cleaner (like what you get for camera lens or eyeglasses) easy to carry in my geek bag , but DO rinse well prior to filling up with something safer than things designed for glass. If you use microfiber 50/50 Iso and '''DISTILLED''' water should be fine. Tap water can have minerals , salts, chorline , tiny grians of sand and other stuff you dont want on the screen surface .
dont use tissue or newspaper , paper towels , old socks or tee-shirts ... these can and will scratch the surface .. Be sure to spray the microfiber , rather than the screen ( drips down into the internals are not good ) . if you dont have a spray bottle , you can just pour a small anmount directly on your microfiber ..
Cleaning the screen while power is off has two advantages , 1stly , you can see dust better against a black background , and obvioulsy there will be less chance of shorting something out if liquid gets where it should not be ..