You can freeze ready-made sandwiches by wrapping in clear plastic wrap and aluminum foil. To reheat, remove the wrapping and wrap in a paper towel. Heat in the microwave for 1 to 2 minutes, or until heated through.
Season pork with flavor enhancer. Place one sliced onion on the bottom of the crock pot, then add pork.
Cover with another sliced onion.
Add ginger ale, cover and cook on low for 8 hours (high for 4 hours), or until the internal temperature reaches 145 F.
Remove pork, strain and save onions, and discard all liquid.
Shred pork with two forks and return pork and onions to the crock pot.
Add BBQ sauce and continue to cook on low for 2 more hours.