With a knife, scrape off any stray hairs from pork ears. Rinse and drain well.
In a pot over medium heat, combine pork ears, vinegar, water, and soy sauce. Bring to a boil, without stirring, and skim off any foam that floats on top.
Add garlic, bay leaves, salt, and pepper.
Lower heat, cover, and cook for about 1 ½ to 2 hours or until meat is very tender. Drain from liquid and allow to completely cool in the refrigerator.
Cut pork ears to about 1-inch sized pieces and thread into bamboo skewers.
In a bowl, combine oyster sauce, banana ketchup, and sesame oil. Stir until well-blended.
Grill skewered pork ears over hot coals, turning as needed and regularly basting with oyster sauce and banana ketchup mixture, until nicely charred.
Serve hot with spiced vinegar for dipping.