Clean and pat the boston butt dry with paper towel.
Rub salt all over the pork.
Pour the liquid smoke over the pork and massage/rub it into the meat.
Instant Pot - pressure cook on high for 2 hours with a natural release (approx. 45-55 min). Note: test the meat for tenderness by stabing center with a fork. If the fork does not easily pierce through the meat, place lid back on and pressure cook for an additional 15 minutes with a natural release. Slow Cooker - cook on low for 12-14 hours or until the meat is tender. This recipe is low and slow to yield a very tender spreadable meat.
Remove the pork and place on a serving tray or in a bowl. Using tongs or 2 forks shred the meat. Optional: season with salt.