If the briquets are not completely dry (an open bag that has sat around in an UN-controlled area can absorb moisture better than a sponge) they will smoke sometimes for the entire cook. Usually this small amount of smoke is harmless as far as my experience has been. Using damp or un-seasoned wood will make smoke and creosote every time.
Webber 22 1/2 OTG Gold, UDS, rusted out chimney, Red Lavatools Thermowand, Maverick ET 732, 1950 model wife. Walking cane to help me get around.