Rinse the drumsticks and dry on paper towels. Whisk together the sweet chili sauce, soy sauce, fish sauce, grated ginger and hot chili oil in a mixing bowl or large measuring cup.
Place the chicken drumsticks in a large plastic bag and pour on the marinade. Marinate the chicken in the refrigerator for at least 2 hours or up to 24 hours.
Remove the drumsticks from the marinade, and stretch the chicken skin to cover the meat. Place drumsticks skin-side up in the crock pot, and cook on high for 3 hours or low for 6 hours
Meanwhile, make the dipping sauce by whisking together all the ingredients. Set aside.
When the drumsticks are cooked, preheat broiler. Remove drumsticks from crock pot and place skin side up on broiler pan. Broil until browned. This will take 2-5 minutes depending on heat.
Brush the drumsticks with a little additional sweet chili sauce, so the garnishes will adhere to the chicken. Sprinkle with toasted sesame seeds and chopped cilantro. Serve the drumsticks with dipping sauce.