Can I put out a cigarette on aluminum MacBooks?

Much more impressed if they can use a macbook to ignite the cig.

Do you remember the movie "Office Space" and the "jump to conclusions mat"? There's a law of nature that all SO answers must be about 9 steps ahead in a different direction from the question. A much more correct interaction would be "can I turn my macbook into an ashtray?" "Yes, just make sure to remove all the plastic first"

My instantaneous reaction was someone's making an art exhibit and their macbook ashtray will be sitting right next to their vintage Mac aquarium conversion. Or they have a broken mac and want the weirdest possible ashtray for their company smoking area.

yes you can, now if it is alight then that right there is an expensive ashtray and and beyond chemical oxidisation increase the ask can and eventualy will get sucked into the parts you just don't want dust and ash. Be that keyboard build up or sucked into intake vents. Then there is the tar buildup from the smoke.

So the real question is why would you do that and it will only increase the probability of issues down the line, maybe not right there, but one day.