Spray 3- to 4-quart slow cooker with cooking spray. Place pork in cooker. In small bowl, mix brown sugar, salt, thyme, pepper sauce, garlic, tomato paste and chiles. Spread mixture over pork.
Cover; cook on Low heat setting 8 to 9 hours.
Remove pork from cooker; place on large plate. Shred pork with 2 forks; return to cooker and mix well. Spoon 1/2 cup pork mixture on bottom half of each bun. Cover with top halves of buns.