Cooking porridge with slow cooker

Anyone using slow cooker to cook porridge? How do you do it? Tried to use it today and i put the rice and hot water in the slow cooker at 8am. By 11am the porridge was not even cooked - ended up putting the porridge on the stove and it cooked within minutes! Please share how you cook the porridge using a slow cooker. Only reason I was using it as I didn’t want to have to watch the stove as I’m watching over my 10mth old at the same time.