1. Heat smoker or grill for indirect cooking at 275°F. Add favorite wood for smoking.
2. Season pork butt on all sides with 3 tablespoons BBQ rub. Let stand 30 minutes.
3. Smoke pork butt, fat side up, for 3 to 3 1/2 hours until internal temperature reaches approximately 160°F. Remove from smoker and lay fat side down on large piece of heavy duty aluminum foil; sprinkle meat with 1 tablespoon BBQ rub.
4. Wrap butt tightly with foil and return to smoker. Cook another 3 to 3 1/2 hours until internal temperature is around 192°F to 195°F. Remove from smoker/grill and let stand 1 hour. Wearing heat resistant gloves, pull pork, discarding fat and bone.
5. Pour sriracha sauce on small plate. Place remaining BBQ rub.
6. Dip avocado slices into sriracha sauce, then gently press into remaining 1/2 cup BBQ rub. Place 2 slices on each slider bun.
7. Top avocado slices with generous helping of pulled pork, BBQ sauce and coleslaw. Refrigerate leftover pulled pork for other uses.