People might find this behaviour pointless and a waste of time, instead of cutting straight to the point. But I personally think it's a pretty good tactic that works well with Ti based communication.
Step 1) Repeat back their point of view, showing that you understand how they reached that conclusion.
Step 2) Then play the devil's advocate, even if it's your real view point. Make them enquiry about a potentially different view point.
Guess what could be seen as the "manipulative" part here is that it's not 100% clear whether you are revealing your own view point.
Reasoning. 1) Direct confrontations usually make people more stubborn about their view points. This affects most people regardless of type. Really, the only time this doesn't really play out is when people have adopted a mentor-student dynamic. 2) You aren't viewed as an opponent, merely someone facilitating thought-discussions. 3) People assimilating information, or making their own enquiries-research are much more likely to adopt a position than when being told.
Result.Even if you don't get an exact switch in attitude. You'll find this approach often softens their own view points and overtime is more susceptible to change (Assuming your reasoning is sound). Only problem is, this might take effort as opposed to straight up saying "Your approach is rubbish." which is how I feel when I can't be bothered to reason with people.
Writing this all out makes me sound like some schemer. But honestly, this is naturally how I communicate because I don't really like clashes, and more importantly realised that if I truly want to pass on information, clashing is the most rubbish method to correct/informing someone. Arguments are more about reinforcing your own view points and how well they can survive against examination. Discussion is more about passing on information to others. The former can be fun exercise, but it makes you appear more like a bigot. Worse case scenario in the latter is that you'll come across like a teacher. This is often the vibe I get when I see other FJs, or balanced TPs (in terms of feeling and awareness) discuss things.
Which one are you more interested in is the real question. Are you truly interested in correcting individuals for them to learn, or are you merely asserting your own personality and desire for things to be logical?