Add pineapple juice or water and liquid smoke to the Instant Pot.
Cut the pork shoulder into smaller pieces (about 6) and add 3 of them to the pressure cooker. Sprinkle half of the pink Himalayan salt on top. Add the rest of the pieces and sprinkle the remaining salt.
Close and lock the lid and cook on High Pressure for 70 minutes, followed by Natural Pressure Release.
Open once the cooking is done, transfer pork to a large bowl, shred with two forks and add some of the cooking liquid to keep it moist.