Sponge Gourd. Grow your own sponge for exfoliating and cleaning your skin, scrubbing dishes, and cleaning the barbecue grill. When harvested between 4 and 6 inches long, they are a sweet, tasty vegetable that can be stir fried, sautéed, or cooked with meats just as you would zucchini squash or okra. Can also be sliced or diced in a salad like a cucumber. Gourd seeds can be roasted and young flowers and foliage can be cooked as a green. 110 days.