Add the dry rub to the pork and rub it on the meat until evenly coated.
If using a crockpot, put the pork shoulder in the slow cooker and cover with the barbecue sauce, then cook on low for 8-9 hours. If using an Instant Pot, cut the meat into 3-inch cubes. Place ½ cup of water in the Instant pot, then add the pork and barbecue sauce. Cook on high pressure for 45 minutes, then naturally release for 10 minutes. Finally, quick release to unlock.
Remove the pork from the crockpot or Instant Pot, and shred with 2 forks.
Add the mayo, lemon juice, sugar, vinegar, salt, and pepper to a mixing bowl, and stir until well combined.
Add the coleslaw mix to the bowl and toss until well coated.
Cut the slider buns in half, then place some of the shredded pork and barbecue sauce on top of the bottom buns.
For traditional sliders, add the optional fried onions and the coleslaw, then top with the top buns. For baked sliders, add the top buns, then place in a 350F oven for 10 minutes. Remove the top buns, then add the fried onions and coleslaw. Put the buns back on and serve.
