According to the cooking method used here, you boil the couscous with plenty of water and when it's done you strain it. Straining discards the water and the extra starch so the couscous is not very sticky. Though it's not necessary, rinsing it before using it in salads is recommended because the couscous remains fluffy and not sticky. This way it can be easily mixed it with the rest of the ingredients. Don't worry that you'll lose flavor, because the couscous will absorb all the juices form the salad and it will become delicious.