What is Saltpeter?
1.
Potassium nitrate (KNO3), a substance used in explosives (usually gunpowder) and fertilizers.
Contrary to popular urban legend, saltpeter has no effect on libido, and too many side effects (high fever, etc.) to be used even if it did.
The army doesn't want to kill our soldiers with saltpeter. They want our enemies to do it.
See
2.
a magical formula that they put in your food in prison and possibly in the military also to curb your ability to pop a boner.
you can't even pop a chubby in basic training caue of the saltpeter