You raised a good question, HTRN. NO ONE would zot you for pointing out that the children must have raised a protest of sorts. Perhaps the teacher told them that it was a different substance OR gave them sugar water afterwards. (for the record: I wouldn’t EVER call for YOUR zot, silly bug)
What one might liken it to, however, would have to be almost as gross. Maybe one of the politer things is an ingredient in much “higher quality” imitation vanilla, i.e. a musky extract of dried anal glands of beavers. And that would be very obscure. (The aftertaste of having partaken of too much artificial vanilla ice cream using that stuff is very... peculiar, let me say.)