Sea Urchin in the fridge

Hi so only culinary adjacent here! I am doing props for a film and need to have a couple sea urchins, was just wondering if I'm not needing them to be actually eaten how long will they last in just a container in the fridge/freezer without absolutely reeking, only need to realistically last a couple days just so I'm not scrambling on the day of shooting submitted by /u/SheenEstevezzz