Add the entire jar of grape jelly to a mixing bowl, making sure all jelly is scraped out. Pour in the full bottle of chili sauce. Add the brown sugar, Worcestershire sauce, and sriracha. Whisk everything together thoroughly until the mixture is smooth, fully combined, and the jelly is broken down into the sauce.
Place the little smokies into the crockpot, spreading them evenly along the bottom. If using two packages, add both at this stage.
Pour the prepared sauce mixture over the little smokies in the crockpot. Stir well so every sausage is fully coated and covered in sauce.
Cover with the lid and cook on HIGH for 3 hours. This allows the sauce to thicken and the flavors to blend while heating the sausages through.
After 3 hours, stir to redistribute the sauce. The sausages should be hot, glossy, and sitting in plenty of rich sauce. Serve directly from the crockpot or transfer to a serving plate. Use toothpicks for easy appetizer-style serving.