Sprinkle 1 tablespoon of rub around all sides of the pork.
Heat oil in a large skillet over medium-high heat.
Add pork and brown on all sides. Remove to a plate.
Turn off the heat to the skillet and let cool slightly.
Slowly (keep your arms, hands and face back as it may splatter!) add 3/4 cup of water to the skillet and whisk.
Pour mixture into a slow cooker on low.
Add the vinegar, tomato paste, remaining 3 tablespoons of the Fire-Eater rub, and 2 cups of water to the slow cooker and whisk to combine.
Add the meat and cover.
Cook for at least 8 hours or until the meat is falling apart. If the liquid does not completely cover the pork you may want to turn it every few hours.
Remove the pork to a cutting board and chop.
Transfer the slow cooker liquid to a saucepan over medium-high heat and bring to a boil. Stir in the hot sauce. Reduce heat to a simmer and simmer until reduced by half, stirring occasionally.
Return the meat to the slow cooker and add the reduced liquid.
Serve on buns, on nachos, on baked potatoes... however you prefer!