Well, I kinda had the impression peristalsis loads the cannon, so to speak, while pneumatics fire it.

I think the idea is one of them is convincing someone to not do something they still have the power to do, while the other would be taking that power away completely. There may be a truly foolproof way to disarm a weapon, but there will never be a foolproof way to convince someone of anything due to the unpredictability of people.