code: public function purgeSubscriptions()
  	{
  		$objNotify = CommentsNotifyModel::findExpiredSubscriptions();
  
  		if ($objNotify === null)
  		{
  			return;
  		}
  
  		while ($objNotify->next())
  		{
  			$objNotify->delete();
  		}
  
  		// Add a log entry
  		$this->log('Purged the unactivated comment subscriptions', __METHOD__, TL_CRON);
  	}
docs: Purge subscriptions that have not been activated within 24 hours