Position rack in top third of oven and preheat to 425ºF. Pierce each potato several times with a knife. Pre-cook potatoes in the microwave on high for about 7 minutes or until they give when pressed. Remove from microwave, place into oven and bake directly on rack until tender, about 30 minutes. When cool enough to handle, transfer potatoes to a work surface and cut off the top (about 1/4-inch lengthwise) of each potato. Scoop center of potato from skins into large bowl, leaving about 1/4-inch of potato lining the skin. Mash with milk; season with salt and pepper, to taste. Mix in corn salsa, chips, half of the cheese, half of the cilantro and half of the onions. Fill each of the skins with the potato mixture, mounding it in the center. Top with remainder of cheese. Return to oven and bake until heated through, about 20 minutes. Garnish finished potatoes with sour cream, remainder of green onions and cilantro.