it absorbs all the flavor. Just add it 20 minutes before cooking time ends.
To speed cleanup, spray the inside of the slow cooker with non-stick cooking spray before filling it with ingredients.
Taking the lid off your slow cooker, even just to give it a stir, drastically reduces the heat and extends the cooking time. Only lift the lid if instructed to do so in the recipe.
Do not add cold water to the slow cooker immediately after use as this could cause it to crack. Either add warm soapy water or let the slow cooker reach room temperature before cleaning.