While stationed in Kef I worked the line running the deice trucks and I remember AC leaving with light to moderate frost but not necessarily iced. I can tell you though, the Germans were the most anal crews when it came to deicing. Depending on the aircraft, most US crews were a little more flexible, brave, or dumb (whatever floats your boat). I've seen icing that made the main mounts compress on P-3's
Takes a long time and a lot of water to get those deiced....