CUT tops off peppers; chop tops, then refrigerate for another use. Remove seeds from peppers; discard. Set pepper shells aside.
MIX pork, 1/2 cup of the barbecue sauce, the rice and peas; spoon evenly into pepper shells. Top evenly with VELVEETA.
POUR remaining 1/4 cup barbecue sauce into slow cooker; stir in water. Stand stuffed peppers upright in slow cooker; cover with lid. Cook 5 to 7 hours on LOW (or 2-1/2 to 3-1/2 hours on HIGH).