Place the onion slices in the bottom of a slow cooker. Sprinkle the pork with the salt, pepper and garlic powder, then place it on top of the onions. Crack open the can of pop and pour it over the whole thing. Add the whole bottle of BBQ sauce and the hot sauce, then add the brown sugar to the liquid and stir.
Put on the lid, set the slow cooker to high and cook for 6 hours. When it's done, the pork will be dark and weird and wonderful. It'll also be fork-tender. That's when you know it's done.
Remove the meat from the slow cooker and shred completely. Spoon the fat from the sauce. Return the meat to the slow cooker and keep in the sauce until ready to serve. Divine!