Season meat with salt and pepper.
In a small bowl, combine the water, vinegar, Worcestershire sauce, and cumin.
Pour over meat in slow cooker.
Cover and cook on HIGH for 1 hour
Cook on LOW for a further 8 hours.
Remove roast from cooker (Discard cooking liquid)
Using two forks, pull meat apart into coarse shreds (Discard fat)
Return meat to slow cooker.
Stir in barbecue sauce.
Cover and cook on HIGH for 30 minutes or until heated through.
Serve meat mixture in rolls.
As this is a sweet meat sandwich, I added crunchy coleslaw to the rolls. It was a huge success & there was plenty left over to freeze.