Soak sixteen (10-inch) bamboo skewers in water overnight.
To make the marinade, in a blender, combine all of the ingredients and process until smooth. Transfer to a large bowl. Rinse out the blender.
Slice the pork against the grain on a 40-degree angle into pieces about 1 1/2 inches wide, 2 inches long, and 1⁄4 inch thick. Transfer the pieces to the marinade and mix well. Cover and refrigerate for 6 to 12 hours.
To make the sauce, meanwhile, toast all of the chiles in a 12-inch frying pan over medium heat, turning to color evenly on all sides, until fragrant and darkened, about 5 minutes. Transfer to the blender, add the tamarind, sugar, lime juice, and fish sauce and process until smooth. Transfer to a 1-quart saucepan, place over medium heat, bring to a boil, and cook for 1 minute. Remove from the heat and let cool. Taste and adjust with more fish sauce if needed. The sauce should taste sour first and then equally sweet and salty. Stir in the cilantro and set aside. (The sauce can be made up to 3 days in advance and refrigerated in an airtight container.)
Divide the pork into 18 equal portions. Thread a portion onto each skewer, running the skewer through each piece as if you are sewing. Then, rather than stretch each piece taut, scrunch it together to form a round bundle that is as tight as possible. If there are any overhangs, tuck them in. The meat should occupy half of the length of each skewer, leaving the other half as a handle.
Light a chimney half full of natural wood charcoal. When all of the charcoal glows in the center and is covered with gray ash, scatter it onto the tray of a hibachi-style grill in a single layer. Position the cooking grate about 3 inches above the charcoal and allow to preheat for about 5 minutes. Oil the grate and arrange the pork skewers on the grate, spacing them about 1⁄4 inch apart. Grill the skewers, flipping them often, until no pink remains and they are charred on the edges, 8 to 10 minutes.
Serve the skewers immediately with the dipping sauce as a snack. Add the sticky rice to make it a meal.