Notifications for anonymous users on nodes they add

I am looking for a module or some kind of workaround e.g. involving Rules, that will allow anonymous users to subscribe to new comments on nodes they have created. My user scenario is as follows:

1. An anonymous user wants to post a new forum topic
2. She clicks on the “Add new forum topic” button
3. On the URL node/add/forumtopic she is presented by the usual form
4. On the form there is an email field with a check box underneath with the label “I would like to receive an email when comments are posted to my thread”
5. She types in her email and marks the checkbox - yes, she would like to have email notifications
6. She submits the form and when a comment is posted in her thread, she gets a notification email with a link to the comment and a link that allows her to unsubscribe from the thread.

I have looked at this nice writeup on goups.drupal.org where different notification modules are compared, but none seems to be offering the functionality I am looking for.

I have installed Comment Notify that offers the desired functionality - but only on comments, not on nodes.
I have tried installing Watcher, but it is early in development and still seems pretty buggy.

This seems to me like a very common scenario - what would be the recommended way of implementing this feature? Any help is very appreciated.