"Ever hear of the word "Coooler" used in this way?"
Not me.

In my experience a "cooler" is a set up poker hand with a predetermined winner, in most cases the takeoff player is the 1 seat. The dealer asks for new decks and then does a false shuffle. I have seen many of them run in back in the KY games.

I know of 2 cases in LV where the large poker Jackpot's were almost taken off with coolers. Both were caught with the cameras. Floorman, dealer, and player got more trouble than they wanted.

In the glory days of LV, stories abound about BJ coolers. Some have to be true. An old timer that worked at the downtown casinos told me they had one BJ 5 deck shoe per day that was run in with winnings split among the pit crew. I don't doubt the stories as they are mild compared to some.