“Kill switches” on equipment are switches that shut the equipment down abruptly and reliably, but usually are not expected to damage the equipment. They're common on things with engines, motorcycles, boat outboards, etc.

It's also a common phrase to say “kill the engine” even if that means just turning the ignition off in the usual way, and again, it doesn't imply damaging the engine.

The kind of switch you're describing would be useful but calling it a kill switch would be confusing to US-English speakers.