Turn the setting on the Crock-Pot to off and disconnect the plug from the electrical outlet. Let the Crock-Pot cool to room temperature before cleaning.
Remove the stoneware crock from the housing. Typically, stoneware crocks simply lift out of the housing. Some crocks do not separate from the housing; cleaning methods remain the same.
Scrape off as much baked-on food as possible with a wood spoon or plastic or rubber spatula.
Fill the crock with hot water and add 1 teaspoon of liquid dish soap. Let the crock soak for one to two hours.
Scrub the crock with a nylon brush or scrubbing pad to remove baked-on foods.
Sprinkle a layer of baking soda over the baked-on food and scrub the stoneware surface with a nylon brush or scrubbing pad if foods remain stuck. Continue to scrub the crock until no baked-on food remains.
Dry the exterior of the crock and place it back into the housing if baked-on food remains.
Fill the Crock-Pot halfway with warm water and add 1 to 2 cups of white vinegar. The amount of white vinegar depends on the size of the Crock-Pot. Add enough water and white vinegar so that the liquid fills the crock three-quarters high.
Place the lid on the crock, plug it back in, and set the slow cooker on a low setting. Let the vinegar and water heat and simmer for two to three hours.
Turn off the Crock-Pot and disconnect the power. Carefully remove the lid to avoid steam burns. Let the slow cooker cool to room temperature.
Pour the white vinegar and water out of the Crock-Pot into the sink drain. Add a squirt of dish soap and scrub the interior of the crock with a nylon brush or scrubbing pad. Rinse the crock with water and dry with a towel.
Wipe the housing with a damp sponge. Dip the sponge into baking soda and scrub baked-on food from the surface of the housing.