Preheat a 6-quart air fryer to 390°F for 3 minutes. Beat egg white with coating water and mix rice flour, cornstarch and salt in a separate shallow dish.
Dip cutlets in egg white, press into a thin flour coating and shake off loose powder. Dab with oil until dry patches are moistened.
Arrange 2 cutlets in the basket and air fry for 5 minutes, turn and cook for 5 to 7 minutes more until lightly crisp and at least 165°F. Repeat with remaining cutlets.
Meanwhile, simmer gochujang, sugar, soy sauce, vinegar, glaze water and ginger in a small saucepan for 2 minutes until smooth and lightly thickened.
Brush cooked cutlets thinly with glaze and return them to the air fryer in batches for 1 minute each. Sprinkle with sesame seeds, rest for 2 minutes and slice into strips to serve.