PreparationPrepare duck: Cut off wing tips with poultry shears or a sharp knife. Remove and discard excess fat from body cavity and neck, then rinse inside and out. Pat dry inside and out and press on breastbone to break it and flatten duck. Marinate duck: Heat peppercorn salt and five-spice powder in a dry skillet over moderate heat, stirring, until hot. Measure out 3 tablespoons and rub 1 tablespoon in body cavity and 2 tablespoons over outside of duck, including under wings and legs. Reserve remaining spiced salt for serving with duck. Put duck in a bowl and marinate, covered and chilled, 8 to 24 hours. Steam duck: Drain any liquid from cavity and put duck in glass pie plate. Rub rice wine over duck. Smash ginger and scallions with flat side of a large heavy knife, then put one third in duck cavity and scatter remainder over duck. Fill wok with enough water for rack to sit 1/2 inch above water and bring to a rolling boil. Wearing oven mitts, put pie plate with duck on rack over boiling water and cover wok with lid. Reduce heat to moderate and steam duck 2 hours, checking every half hour to siphon off fat and juices from around duck and in cavity with bulb baster and replenishing boiling water as necessary. Wearing oven mitts, remove pie plate from steamer. Discard ginger and scallions. Drain duck and cool in pie plate 15 minutes. Air-dry duck: Slide duck onto a rack set over a baking sheet (to catch juices) and pat dry with paper towels. Position duck in front of a fan and air-dry 2 hours, making sure air blows directly onto duck. Fry duck: Heat 2‚ inches oil in large wok or large pot until a deep-fat thermometer registers 375°F. Meanwhile, brush outside of duck with soy sauce, then dust with flour, gently knocking off excess. Dip mesh spoons in hot oil (to keep duck from sticking) before using them to gently lower duck into hot oil. Fry duck, spooning hot oil over top, 2 minutes. Carefully turn duck over and fry 1 minute more. With extreme care, remove duck from oil with mesh spoons, draining cavity, and transfer to paper towels to drain. Heat oil to 400°F and fry duck a second time, in same manner, until dark brown and crisp, 30 seconds to 1 minute on each side. Again with extreme care, remove duck from oil with mesh spoons, draining cavity, and transfer to paper towels to drain briefly. Presentation: Serve duck with small dishes of reserved spiced salt for dipping.