Combine the salt, lemon pepper, white pepper, black pepper, granulated garlic, brown sugar, and chili powder.
Trim all the fat from the point portion of the packer brisket, then separate it from the flat portion. Trim the fat cap on the flat portion until only about 1/8 inch (3mm) of the fat remains.
Cut the point into two equal pieces, then cut the flat portion into two equal pieces, making four pieces total.
Sprinkle the rub evenly on all four pieces of the brisket.
Place the brisket into the slow cooker with the two lean (flat) pieces on the bottom and two fatty (point) pieces on top. Tip: As the brisket cooks, the juices will fill the crock pot up so the flat pieces will be completely submerged. The liquid will braise the flat in the beef au jus and give it a lot of flavor. The two point pieces are above the liquid, so they dry out and form a crust. If the liquid rises too high, use a turkey baster to remove excess beef au jus so the point does not become submerged.
Turn the slow cooker on high and cook for 8 hours.
Check the meat is cooked to your desired tenderness by poking with a wooden skewer or fork.
Remove the brisket and rest for 15 minutes.
Cut the brisket point into cubes and brush on a little barbecue sauce. Slice the brisket flat. Serve immediately.