Lowe's sell parts for Whirlpool washing machines, although its selection is limited. The Lowe's website advertises a Whirlpool detergent cartridge dispenser that evenly releases detergent during the wash cycle. The unit color/finish is blue and it sells for $21.99 as of February 2015.
The Whirlpool parts website offers a wide variety of parts and accessories. Each product description includes an image of the part, model number, part number, availability and unit price. Images are not available for all parts.
A second excellent alternative is the Appliance Parts Pros do-it-yourself website. This site lists over 500 Whirlpool washing machine parts and accessories.