A slow cooker does its work slowly. It likes to be cleaned that way too.
Gentle on the Crock
How to clean a slow cooker, and why the gentle way is also the easy way.

A slow cooker is one of the kindest things in a kitchen. Food goes in, you walk away, and hours later dinner is ready. It asks almost nothing of you.
The cleanup seems like another story. Dinner is over, and there sits a heavy crock with a dark ring baked around the inside, and a lid spotted with dried drips. It's easy to leave it on the counter "to soak" and not come back for a day or two. Most of us have done it.
But a slow cooker won't ask you to scrub hard. It only wants back what it gave you all day: a little patience and some gentle heat. Warm water, a soft sponge and some baking soda do most of the work. The one real rule is to go easy on the crock.
First, do nothing at all
Turn the slow cooker off and unplug it. Leave the lid on and let the whole thing cool completely. That can take an hour or more, because the crock is thick and holds heat for a long time.
The crock is tough, but it doesn't like sudden changes. A hot crock that meets cold water can crack, sometimes right away and sometimes later, from a small hidden line.
So the first step is the easiest one. You don't have to do anything. Just let it rest.
Two parts, two kinds of care

Most slow cookers come apart into three pieces: the crock, the lid and the base.
Fill it before you sit down
The easiest time to clean a slow cooker is soon after you use it, once it's cool. Fill the crock with warm, soapy water before you sit down to eat, and it will be ready to wash when you're done.
Wipe the base whenever you see a drip, so spills don't bake on the next time you cook.
Slow in, slow out
Some things in the kitchen need force. The slow cooker isn't one of them. Give it time to cool, warm water to soak in, and a gentle hand. It was gentle with you all day.

Let it cool, let it soak, and go gently. That's all it asks.
