Place the trimmed pork loin into the bottom of a slow cooker.
In a small mixing bowl, whisk together the orange juice, lime juice, dried oregano, cumin, garlic powder, onion powder, sea salt, and black pepper.
Pour the citrus and spice mixture over the pork, ensuring the meat is well coated.
Set the slow cooker to low and cook for 6 to 8 hours (or high for 3 to 4 hours) until the pork is tender enough to shred easily.
Remove the pork from the slow cooker and use two forks to shred the meat into bite-sized pieces, then return it to the pot to soak up the remaining juices.
Heat a dry skillet over medium-high heat and warm the corn tortillas for about 30 seconds per side until they are slightly charred and flexible.
Divide the shredded pork evenly between the two tortillas.
Top the tacos with diced red onion, fresh cilantro, and a drizzle of salsa verde before serving immediately.