Etymology of the phrase "gone clear", meaning "died"

I take part in a music forum dedicated to resonator guitar (Dobro), and people there have used this phrase a few times, most recently in reference to bluegrass Dobro legend Josh Graves, who died last week.

Someone asked about the phrase’s etymology, and no one was really sure. It was suggested that it had roots in the West Virginia-Ohio region (although, FWIW, I’m from WV, and never heard it).

Anyone know?

It evidently means “gone clear of this world” at least that’s a person’s take on it in this message board exchange…“gone+clear”+died+phrase&hl=en&gl=us&ct=clnk&cd=12

Do you think that this is what Leonard Cohen means in Famous Blue Raincoat?

I don’t know why I find that song so haunting. If he’s asking the guy if he killed himself, that makes it even more haunting.

It’s not from the Scientology concept of “clear”?

Kinda like us AA members describing a deceased member as “forever sober”?

Yeah, I was thinking it was something along those lines. Ham operators will say a deceased peer has gone “silent key”.

Many of the Google cites I found were related to Scientology. But I don’t know if it was a coincidence.