In a large bowl, combine soy sauce, banana ketchup, brown sugar, garlic, oyster sauce, calamansi juice, black pepper, and paprika. Mix until the sugar dissolves.
Add the sliced pork to the marinade and toss well to coat every piece evenly.
Cover and refrigerate for at least 4 hours, preferably overnight, for maximum flavor.
Thread the marinated pork pieces onto the soaked bamboo skewers, weaving the meat back and forth for even cooking.
Preheat a grill or grill pan to medium-high heat. Lightly brush the grates with oil.
Place the skewers on the grill and cook, turning frequently. Baste occasionally with the remaining marinade during the first part of cooking.
Continue grilling until the pork is fully cooked and develops caramelized edges with slight char marks.
Remove from the grill and allow the skewers to rest for a few minutes before serving.
For the dipping sauce, combine vinegar, soy sauce, chili, and garlic in a small bowl and stir well.
Serve the pork skewers hot with steamed rice and dipping sauce.