Which would you use to stomp out rumour?

I think I would neither stomp out nor quash rumour. Isn't rumour something irrational whispered or babbled around? I think it's not in the nature of a rumour to be stomped or quashed. It's like you can't quash ghosts. Or wind.

@tsuwm. Is this one in this special dictionary? mediacracy not to be confused with mediocracy? Just because recently I read this word.