A short while back, I bought a wagon which had been smoked in. Following the advise I read somewhere on this forum, I wiped down all the interior surfaces with a mild solution of white vinegar/water.

I thought that had worked its magic, but last night I noticed the smell of stale cigarette smoke coming from the vents right after I turned on the A/C.

Has anyone found a method to eliminate this lingering smell without pulling apart the heating/ventilating system for a thorough cleaning or masking it with an even heavier odor?