In a colander or sieve, rinse and sort through the dry pintos. Check for any unwanted debris and discard. Pour rinsed beans into the bottom of a 4-6 quart slow cooker. After beans are in the pot, layer the onion and garlic, followed by the pork shoulder. In a mixing bowl, combine the contents of the seasoning packet, chili powder, cumin, salt and pepper with the 12 oz. beer and pour it all into the slow cooker. Add the remaining 5 cups of water. Cook on high for 8 hours, until pork is completely tender and falls apart easily. (Remember that removing a slow cooker lid during cooking will always extend the amount of time) Using 2 forks or a wooden spoon, begin to break apart the pork. Add in the salsa and green chiles. Stir to combine everything and keep the slow cooker on warm until ready to serve. Serve over your favorite corn bread and top with more Salsa Verde and Cilantro-Lime Sour Cream (see recipe below).