What, pray tell, is glib? Your description has me imagining all different sorts of things!
Sorry, I was being silly in an attempt at humour. Glib is the act of being smooth-talkingly insincere. It came up in a whatsapp chat with a friend who accused me of being glib. While it's a quite negative thing to be called I was amused and didn't mind the comment. Then I imagined having a big load of glib to hand and decided if it were a physical thing it'd be shiny greasy puddingy stuff in a tub.
There's a glimpse into how my mind works that no-one wanted.