I strongly suggest you use a liner, this will make the removal of the moisture/grease a lot easier which you need to do later.
Normal pulled pork cuts are done with a Butt or a Shoulder cut.
Spray the liner with pam.
In 6 quart or larger slow cooker put a few slices of onion down and then place the Butt Roast and put the rest of the onion slices on top.
Pour the pineapple juice over the top of it.
Cook for 4-5 hours on high.
You can also cook this on low all day for about 8 hours but will still need to do the next step, so this is not a great recipe to do while your at work and come home and finish and have the ability to eat once you get home…FYI.
After the 4-5 hours, pull out and put in a bowl, as your pulling apart with a couple of forks, remove any fat.
Add the Barbecue Sauce and shredded onion, and mix well.
If you have used a liner you can easily pull out the liner and discard the entire contents into the trash.
If you have not used a liner you will need to carefully drain all the liquids out and clean the crock-pot.
Since I’m all about not scrubbing the crock-pot I put in a new liner and put in the pulled-pork, and now put on low for about 3 hours stirring about half way through.