My two cents worth:
I have only used "Used Dryer Sheets" on my iron. It has never stained my ironing board cover and very nicely removes sticky stuff from my iron. I can see how a new, unused dryer sheet could make a mess.
We only use "unscented" dryer sheets so no unwanted smells.
As for cigarette smoke, DH and I can not ride in our sons car. He does not smoke, and does not allow his friends to smoke in his car, but they ride in his car and the smell transfers from their clothes to the car. Same way if one on them walks through our house. The smell lingers for hours even though they did not smoke inside. When his car broke down, he borrowed DH's truck and tried to cover up the smell with fabreeze! We told him next time to not use fabreeze and to drive with the windows open even if it is freezing outside. DH said the smell of fabreeze mixed with smoke was enough to make him gag and he used to smoke! He quit before I met him.
I grew up with smokers. I was used to the smell as a kid, but now, the older I get, the harder it is for me to be around it.
My step mother made us a beautiful, king size scrappy quilt. Both she and my father smoked. I took the quilt to the cleaners and they were unsuccessful in taking the smell out. I wound up putting two damp towels and several dryer sheets in with the quilt and ran it for a couple of hours on cool. Took the smell out.
Sorry, that was way more than two cents worth! LOL