If you properly stretched your neck so that your face front is horizontal rather than just using your eye movement to look upwards the swallowing mechanism cannot technically work. The neck has to be more in it's normal position otherwise the muscles that are used cannot do what they normally do during the swallowing action. I just asked everyone in our house if they can do it and they can't....unless they don't lift their head up enough. I found that my dogs had great difficulty swallowing if I held their heads up. Thats why I hold their heads in normal position now.

The only other way to do it is if you life your chest and shoulders to hunch them whilst looking upwards because this puts the throat back into it's more usual position but, if not, it can't be done.