How to clean the dispenser on a top-loading washing machine:
First, find your dispenser: This may be in the top of the agitator (that’s the plastic cylinder in the middle of the washer drum), or may be located elsewhere depending on the make and model of your washer. Then, make sure the machine is powered off and all laundry is removed. Finally, clean with a warm, wet washcloth. To avoid residue buildup, clean the dispenser every five to 10 washes, or about once a month.
TIP: You can use a toothbrush for hard-to-reach corners and harder buildup.