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)