Place the chicken breasts on the bottom of a slow cooker set to high.
Mix together the pineapple juice and soy sauce. Pour it over the chicken then pour over the BBQ sauce.
Cook covered on high for 4 hours. Remove chicken from the slow cooker and pull apart using two forks.
Place back in slow cooker and leave uncovered for a few minutes. Make sure sauce is mixed into the chicken.
Serve with extra BBQ sauce.
Notes
To cook on the stove follow the above instructions except cook in a large covered sauté pan on medium heat for about 20 minutes or until tender. Once pulled chicken in put back in pan simmer on low uncovered for about 5 minutes so sauce thickens a little.