Add the water to the crock.
Season the corn with salt & pepper and add it to the slow cooker (or melt some butter in the microwave and brush it on the corn before seasoning).
Put a slice of butter on each ear of corn.
Cover with the lid. Cook 3-4 hours on High, or 5-6 hours on Low until the corn is bright yellow and heated through.
When done, remove the corn using tongs. Then add more butter, if desired, and more salt and pepper to taste.
Add any of the optional ingredients to the hot corn, if using.
Serve hot.