Here's a non-smoked recipe that works great in the Cookshack:
2 Tbsp catsup
2 Tbsp brown sugar
1 Tbsp hoisin sauce (in the Asian food section)
1 Tbsp soy sauce
1 tsp TenderQuick
1/2 tsp ground star anise
1/2 tsp ground ginger
1/2 tsp ground white pepper
Mix together and rub over a 1.5 to 3 lb piece boneless pork butt. Marinate 4-6 hours in refrigerator. Roast in smoker with no wood at 225F until well-done but not falling apart (170F internal). Cool and dice or chop for use in stir-fries, fried rice, dumplings, etc. Or cut into large pieces and freeze for later.
(Adapted from Dim Sum by Rhoda Lee)
This recipe shows how a smoke ring can come about with no smoke. 4-6 hours marinating will give 1/4 or 1/2 inch ring, which seems about like the BBQ pork at the Chinese grocery.