First, take your Crockpot and spray it with a non-stick spray. Any brand will do, just be sure to make sure you have a thin coating all over the inside. Next, pour in the Oyster Crackers. In a small bowl or glass measuring cup combine the Ranch seasoning packet, garlic, dill, and vegetable oil. Mix with a whisk or fork until it's well combined. Pour over the Oyster crackers. Mix the Oyster crackers until the seasoning mixture is coating all the crackers. Set the Crockpot to low, cover, and cook for 1 hour. Be sure to stir the mixture every 20 minutes or the cracker could burn. After an hour, remove the lid and add in the butter. Stir until the butter has melted. This will take about 5 minutes or so. Turn off the Crockpot. Then add in the parmesan cheese and stir until the crackers are coated. Now they are ready to enjoy! I suggest serving them in another bowl as the Crockpot will still be very hot. You can also store these crackers in an air-tight container for about a week. This is a great snack! Perfect for munching on while watching a movie. Works well for charcuterie boards too!