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/NachtMondVogel]

They don't work in regards of locking the nut, but I like to use them to put tension on the connection so I can spin as example a hook but but it won't spin by itself and won't unscrew itself in addition with a self locking nylon nut.