Mark out a hole on both ends of the cooler, you will need one hole on each end. The bottom of the hole should be at least 4 inches from the bottom. Use the outside rim or end of the dryer hose to trace your hole with the marker so that you will achieve the correct hole size. Carefully use the utility knife to cut both holes out.
Measure how much length you will need for the dryer hose. Typically, 3 to 4 feet of hose will do the job. You will need enough length to cross through the ice chest from one end to the other and then turn and reach the fog machine located about 18 inches above the hole. The fog machine should sit on the cooler's lid for best performance. After cutting the proper hose length, fasten and clamp one end of it to the fog machine, which should be mounted on top of the ice chest.
Cut a slit a few inches long in the closed end of the shopping bag, around the middle of the seam. Slip that hole over the few inches of hose coming from the output side of the ice chest. Apply some duct tape to better seal the plastic bag to the hose; it does not need to be an airtight connection.
Open a bag of ice and drop all contents into the bottom of the ice chest so the level is right beneath the hose that crosses the chest. Turn on the fog machine and fog should begin to appear within 30 seconds.