Delete all watched videos in YouTube Playlist

delete-watched-videos-from-playlist.js

(function() {
  var i = window.setInterval(function() {
    var watched = document.querySelector('.watched');
    var closeButton = watched ? watched.parentNode.parentNode.parentNode.querySelector('.pl-video-edit-remove') : false;
    if (closeButton) {
      closeButton.click();
    } else {
      window.clearInterval(i);
    }
  }, 500);
})();