Saltwater and Switcheroo

You are Dex Fino, small-time caper artist, and today's prize is a single jar of Grandma Opal's Original Sea-Smoke Taffy — the only batch made with her secret recipe, locked behind the glass counter of Wavecrest Confections. The shop's owner, Rella, has stepped into the back to pull a fresh batch, leaving only her insufferable nephew Cort behind the register. Cort has seen your face before and watches every customer like a lighthouse beam. The jar sits right there, tantalizingly labeled in Opal's own handwriting. You have maybe five minutes before Rella returns.