Place pork in a large slow cooker.
Mix together orange juice, lime juice, and liquid smoke in a bowl. Add onion powder, garlic powder, paprika, Mexican oregano, cumin, cayenne pepper, salt, and black pepper and stir well to combine.
Pour the marinade over the pork to cover it completely. Add bay leaf, making sure to submerge it in the liquid.
Cover and cook on LOW for approximately 8 to 9 hours, or until the internal temperature of the pork reaches 155-165 degrees.*
Transfer cooked pork to a cutting board and let rest for 1 hour. Reserve juices for later use in other recipes.*
Pull the pork by hand, picking out and discarding excess fat. Store in the fridge for up to 5 days, or in the freezer for up to 3 months.