Self-Destruct Button

Q: Why did I install that button?

A: Because you're stupid.

If the heroes can't destroy the Villain's weaponized machine, they could hit the Self-Destruct Button. It always destroys the machine in a single go. Bonus Points if they kill or seriously injure the Villain in the process. More Bonus Points if they already badly damaged the machine before pressing the button, thus making it unnecessary to press it.

This UnTrash is notable for being very counterproductive, irresponsible, and plain stupid. The entire idea of installing a button that makes whatever machine it's applied to essentially commit suicide is a level of stupidity and Plot Convenience that many UnTrashes could only wish they could achieve.