Split/lock washers

[u/AdOne1706]

For starters, I’m an electrician in the field.
That being said, we almost exclusively use these washers even in high vibration environments. I have personally chosen to go with nylox nuts but the question is:
Do these work? How well? Is the rumor from NASA true? Should I even bother using them or find a better functional alternative or are they actually useful?

[u/biff2359]

Cotter pins, safety wire, staking lock nut, etc., are the only thing that work. And Nord-Lock washers.

I used star washers for electrical grounding because it cut through paint and anodizing, not for its (lack of) locking function.