Take the dispenser drawer out of washing machine occasinally and wash it in dishwasher.

Just wash it in the sink using ordinary washing up liquid. Rinse well, then replace.

Mine gets cloggeed easily. To remove hard softener etc fill the sink up with hot water and leave the drawer to soak for about 5 mins. then with the scourer side of a spong wash clean.

I wash it out with dish detergent and to remove really dried on crust soak, sprinkle with bicarb, rub with lemon or vinegar and scrub. (Kim & Aggie tip, not mine)