The only reason why Apple says what is says below is because of the potential of liquids getting into the phone from accidental spillage. All would wreak havoc if spilled into the vents. You can use alcohol wipes from Zweiss to clean the screen and it will not remove the coating. I use them on my eyeglasses all the time, and it does not damage the coating on the glasses or my iphone.
"Don't use window cleaners, household cleaners, aerosol sprays, solvents, alcohol, ammonia, or abrasives to clean iPhone. The front glass surfaces have an oleophobic coating. To remove fingerprints, wipe these surfaces with a soft, lint-free cloth."