Remove the husks from your cobs of corn and place them in your slow cooker. Add the water. If you're doing more corn in a larger slow cooker (I used a 6 quart Crock Pot for 4 cobs of corn), double the amount of water used.
Cook on high for three hours.
When the corn is done, drain the water and stir in butter and salt to taste, or serve the corn as-is and let everyone add what they like at the table.