I drank it. It was a creepy quest but it didn't seem like anything happened from it. I just got quest completion img, energy and quoins at the end but not img throughout the quest.
And the need for the music to be up? I didn't notice anything to do that required that. And I answered butter side up.
I ended up dying from No-No Powder Crash immediately after starting, and now I'm stuck with my quests telling me I'm all ready doing it as I stand in Groddle Forest.
I went to the source to get the water - the watercooler in the Bureaucratic Hall. I knew instantly what it meant by 'funny-tasting water' to unlock the quest.
It was interesting.