Anyone who's ever set up direct deposit knows how this works. It's almost common sense.

I imagine most people have not done that (I've mostly seen that when linking accounts like brokerage accounts online), and I don't think it's common sense.

For setting up direct deposit at most workplaces (in the US, at least), you just give HR your bank routing and account numbers when you start and that's it. I've never gone through any kind of verification process.