You can click on 'unwatch' for it to not appear in your 'watchlist' anymore. By doing that, you can select the topics you're wanting to follow.
its the best answer for unfollow a post or thread. or just avoid the post and keep eyes on your destination post or thread.you can now lock this thread for preventing the signature spamming .just lock this thread now.
Hope you have got you answer and solution.
It was damn lazy questin