From Fry and the Slurm Factory

Grunka Lunka's:
Grunka lunka dunkity doo
We've got a friendly warning for you
Grunka lunka dunkity daces
The secrets of Slurm's on a need to know basis

Asking questions in school is a great way to learn
If you try that stuff here you might get your legs broke
We once found a dead guy face down in the Slurm
It could easily happen again to you folks

So keep your head down and keep your mouth shut
Grunka lunka lunka dunkity dot!

Later at the secret door:
Grunka lunka dunkity-gredient
You should not ask about the secret ingredient!
Grunka lunka dunkity darn guards...