Place onion rings and garlic on the bottom of the slow cooker.
Blend the dry seasonings, and rub into pork roast.
Place pork roast on top of the onion rings, then add liquid. You could use any combination of fruit juice, vinegar, broth, beer or water.
Cook on low 8-10 hours.
Remove the pork from the slow cooker, leaving the excess liquid behind.
It should be easy to shred it with a fork.
Serve with or without a bun, and with or without BBQ sauce.