Add pork pieces with ⅔ cup teriyaki sauce, salt, crushed red pepper and pineapple juice to a large zip lock bag
Seal the bag and toss to incorporate the ingredients thoroughly and refrigerate 1-2 hours
Remove pork from the bag and discard marinade
Thread pork evenly onto skewers along with pineapple chunks and red onion
Preheat the air fryer to 375 degrees F (190 degrees C)
Lightly coat the air fryer basket with cooking spray and cook skewers 15 minutes, flipping halfway through
Stir remaining teriyaki sauce with water in a small bowl and microwave until warm
Sprinkle skewers with green onions and serve with sauce
