Spray the slow cooker with cooking spray and add the pork roast. In a small bowl, combine the duck sauce, garlic, ginger, chili paste, rice wine, soy sauce and sesame oil. Whisk in the cornstarch. Pour the sauce over the pork.
Cover the slow cooker and cook the roast until fork-tender and an instant-read thermometer registers 160 degrees , 3 1/2 hours on high heat or 8 hours on low heat. Transfer the pork to a platter, cover with foil and let stand for 10 minutes. Pour the cooking liquid into a bowl and let stand for 10 minutes, then skim any fat from the surface.
Slice the pork and arrange on a platter. Sprinkle the scallions and cilantro on top. Serve the Asian sauce on the side.