“Ring in a cooler” implies that you are swapping out a ‘hot’ deck (where the order of cards has been lost due to the act) with a pre-arranged (cooler) deck for your finale.
“Ring in a cooler” is a terminology used both in gambling and magic, which means to switch in a stacked deck or a deck that has been placed in a specific order.
“Ring in a cooler” is magic talk for swapping out a deck where the order of cards has been lost, with a pre-arranged (cooler) deck.
“Ringing in a cooler” is a term used by old gamblers. It is a slang for switching in a cold (stacked) deck.