Rinse and pat ribs dry. Remove thin membrane from back of ribs by slicing into it with a knife and then pulling. (This makes for more tender ribs and allows smoke and rub to penetrate meat better.)
Sprinkle meat evenly with Cajun seasoning, and massage into meat. Let stand at room temperature 30 minutes.
Soak wood chunks in water for at least 30 minutes.
Prepare smoker according to manufacturer's directions. Bring internal temperature to 225° to 250°; maintain temperature for 15 to 20 minutes.
Drain wood chunks, and place on coals. Place rib slabs in a rib rack on upper cooking grate; cover with smoker lid.
Smoke ribs, maintaining temperature in smoker between 225° and 250°, for 3 1/2 to 4 hours. Remove ribs from grill, and wrap in heavy-duty aluminum foil; return ribs to smoker. Cover with smoker lid, and smoke 30 more minutes. Serve with barbecue sauce.
Note: For testing purposes only, we used Luzianne Cajun Seasoning.