Place couscous in a fine-mesh strainer and rinse under cold running water. Dump couscous onto a half-sheet pan, sprinkle with salt, and let stand until grains swell, about 10 minutes. Break up lumps with your fingers.
Partially fill a large steamer pot or stockpot with 1 inch water and bring to a simmer. Place a damp tea towel in the steamer or colander and add couscous. Fold towel over couscous and steam, covered, over simmering water for 15 minutes.
Pour couscous onto large, rimmed baking sheet and sprinkle with 1/2 cup cold water. Toss with slotted spatula until cool and the water is absorbed. Spritz hands with olive oil and spread out couscous, breaking up any lumps as you go. Set aside for 5 minutes.
Refill pot with 1 inch of clean water and return to a simmer. Return the couscous to the colander or steamer lined with the damp tea towel and steam, covered, for 10 minutes.
Transfer steamed couscous to a large bowl and serve family-style.