Ball up 4 large pieces of tin foil and place in the bottom of the slow cooker.
Combine garlic powder, onion powder, salt and pepper in a small bowl. Massage spice rub into pork ribs.
Set pork ribs on the foil balls inside the slow cooker.
Cook on low for 6-7 hours.
Remove ribs from the slow cooker and place on a large cutting board. Let cool for 10-15 minutes. Remove any bones or cartilage from ribs.
Using a knife, cut up the ribs into pieces. The meat will break apart as you chop. Continue to chop until the pork is in small, shredded pieces.
Use your slow cooker pulled pork immediately, or place it in zip top freezer bags and freeze for later use.