I love them, it's a great way to outline essentially what will happen if the party doesn't stop it all while nice and concise!  You can do clocks for positive things as well, I've used them for relationships before with someone trying to court an NPC. In that case, they would make rolls that could advance the clock, or when they did narrative things to do that!<br/><br/>Hahaha!  Hopefully it doesn't come to that! Though, you know what? Who knows! Maybe it will!