Which version are you using? If it's English/North America, you don't have the tools necessary to turn on RTL text flow in the interface. (The documentation is less than clear on this matter.) If you're a Creative Cloud user, I believe you can download a Middle East version of ID at no additional cost - if so I am sure I can dig up a thread with instructions.
If you're using a plain ol' retail license, then you'd need to use a script, or buy a plugin, or buy the full retail ME edition in order to get at the RTL text control tools. The WRC will let you typeset LTR-direction complex scripts, like Thai and Lao and Hindi, but if you need Arabic or Hebrew or another RTL language then you'd need some way to turn those tools on (free script, inexpensive plugin, expensive full ME edition).
Yes, I'm using an English/NA version. Guess that's one feature I won't be
able to use.
Ken Falk Marketing & Communications
Phone: 301.424.3694 Email: email@example.com
Thoughtful creative just slightly outside the box
Oh, you can absolutely use it, if you are willing to invest forty-five minutes in installing some stuff and testing it out. All of the scripts and templates discussed in this post still work, I think. That's your free option. I personally use in-tools.com's World Tools, which is my favorite of the relatively inexpensive plugins that allow us access to the under-the-hood undocumented RTL features.
Here is a much easier answer from Lynda.com for FREE!
No matter how you flip text around on a path, you're not going to get true RTL text behavior. Such behavior is necessary for laying out languages like Arabic, and you won't be able to simulate those behaviors in this way.
That being said, the link you posted does describe a really cool technique. It's just not an answer to this particular question.