Place Boston Butt in a 6-quart slow cooker, fat side up. Pour barbecue sauce and coke on top.
Cover and cook on low for 8 to 10 hours. Meat should shred easily with a fork.
Remove pork from crockpot and place in a large bowl or on a large plate. Shred with 2 forks. Discard any chunks of fat.
Skim fat from sauce and return pork to crockpot.
Notes
The pork will give off lots of liquid as it cooks. If you like lots of thick barbecue sauce on your pork, have an extra jar of barbecue sauce on hand and add some just before serving.