Place the pork in the slow cooker and season with apple cider vinegar, liquid smoke and salt. Add apple juice to the slow cooker, cover and cook low 8 to 9 hours.
Remove pork and transfer onto a large dish; reserve all the liquid into a cup and set aside.
Shred the pork with two forks and put it back into the slow cooker along with about 3/4 cup of the reserved liquid and the Oregon Trail sauce.
Cook on high 1 more hour.
Serve on buns with shredded cabbage and more sauce if desired.