Side-note: for me, at least, "salty" isn't anything to do with tears; in my idiolect when someone's "salty" it doesn't mean they're sad, it means they're angry or offended or something along those lines. The metaphor is more about how salt (in large quantities) tastes strong and sharp.

(Which maybe illustrates that a metaphor can succeed even when everyone doesn't agree about just what it's referring to, as you're suggesting "call" may have done.)