I used a barbecue sauce with an upped ante - I used a small amount of fajita seasoning and a can of coke over the 4 days, just to make it sweet and spicy.
I made pulled pork for the first time a couple of months ago. Would never ever buy it from the shops again, slow cooked the beast of a pork joint in a slow cooker for 4 days...... never eaten anything like it, serving it up with creamy american style mash and barbecue beans. Proper comfort food...