Cut slits with a knife into the pork and stuff half of the garlic into the slits. Combine remaining garlic, jerk seasoning, and course salt and rub over the pork.
Squeeze lime on the top and pour orange juice on top of the pork. Cover and marinate pork for 5 hours or overnight.
Spray your slow cooker with cooking spray and place pork and juice into the bottom of the slow cooker. Cook on low for 9 hours.
Once the pork is cooked and tender, remove the juice and reserve 1 cup. Shred the pork and pour the 1 cup of juice back into the slow cooker. Let cook for an additional 15 minutes.
To make the caribbean salsa:
Add the diced mangos, avocado, and red onion. Add cilantro and lime juice and salt and pepper to taste. Serve over the pork.