Cut your pork into large chunks. This is so that the meat fits into the GoSun cooking tube.
Mix yellow mustard, Worcestershire sauce, and apple cider vinegar to create a base help the rub stick to the meat. Brush this mixture onto all sides of the pork roast chunks.
Cut slits into the pork. You will want as many slits as you have garlic slices. Slip a slice of garlic into each slit.
Combine the brown sugar, salt, pepper, chili powder, and BBQ rub in a bowl. Rub this mixture into the meat, ensuring all sides are well-coated.
Place the prepared meat into the cooking tube of your GoSun solar oven. Cook for approximately 3 hours.
Carefully remove the meat from the GoSun cooking tube, leaving the liquid behind. Reserve ¾ cup of the cooking liquid and discard the rest.
Shred the pork and return it to the cooker. Stir in the reserved cooking liquid and 1 cup of BBQ sauce into the shredded meat for added flavor. You can add more or less liquid and BBQ sauce to your taste. Cook for another 30-60 minutes.