In a separate bowl, add in the garlic powder, onion powder, black pepper, cayenne pepper, and vinegar. Whisk together until incorporated.
Pour the vinegar and spice mixture into the crock pot and over top of the pork shoulder.
Add in the water and oil by drizzling it along side of the pork shoulder. Pouring the water over top of the pork will wash around the seasoning you just placed on it.
Set the crock pot to low and let it cook for 8 - 10 hours. I prepared mine the day before and placed it in the fridge overnight.
Shred the pork using two forks. Mine was completely cool, so I used my hands and shredded mine.
Pour off all the juice except for ¼ cup.
Add in 1 cup of your favorite barbecue sauce and stir until it coats all the meat. Place the slow cooker on low and heat until warm. Mine was completely cold, so I set mine on low for an hour.
I laid out 20 crackers and placed a slice of cheese on each. I then added a small pile of pulled pork to each cracker. Place them on a serving plate and help yourself!