[Idiom] As still as salt

[mrtke]

Recently, I've encountered the expression "as still as salt" (Peter Pan and Wendy by J.M. Barrie). I know this (or similar) phrase was also used by William Dean Howells, but I haven't found it anywhere else (to say nothing of dictionaries). I wonder whether "(as) still as salt" is a fixed phrase/idiom or just licentia poetica.

 

[Raymott]

It may have been an idiom once. I haven't heard it.

 

[emsr2d2]

I've never heard it either.

 

[Rover_KE]

It's definitely not a fixed expression or idiom.

I can't see the reasoning behind it anyway. You should avoid using it yourself.

 

[mrtke]

I can't see the reasoning behind it anyway. You should avoid using it yourself.

When it comes to "the reasoning", an association with Lot's wife (forever still) occurred to me.
Thank you, I'm not going to use it.
I simply needed to make sure.