I was so pissed when I went out and bought a liter of Mountain Dew and tried this little experiment. It did NOT glow! After I tried it twice, I went online and found a forum where apparently a bunch of people have tried this and they had the same results that I did. POO! Apparently someone analyzed the video and noticed that there was an edit and the bottle was turned. Also a 1/4 bottle of Mountain Dew would not be enough to spell “David” at the end the of video.
Conclusion: he broke a lot of those Glow Stick things and put them in the bottle.