Every one of my 560 listings has the following:

"My items come from a home with over 200 non-smoking teddy bears, however their owner does smoke. Each item is aired outside before posting. If this is likely to offend you, please do not buy."

It is in italics so it does stand out.  I do everything possible to eliminate any cigarette odour (non smoking craft room), however I am aware that smoke gets into everything.  I'm quite often asked "wouldn't you get more sales if you left the smoking bit out?", and the answer is most probably.  Someone once said "honesty is the best policy":-)