So Fe being IXTPs inferior- You'd manipulate them using something like: "You will never be able to fit in with society, unless you do this", (though it would have to be more subtle). I would think that you could play to their need for competence more than that. And I think that falls into the Enneagram category.
If I told an ENXP that they suck at remembering sensations, they would likely agree... maybe even laugh. IXTPs would also laugh and agree when you tell them that they suck at Fe. It wont affect them if they identify with it.
Playing to the Doms seems like it could work though. Telling an ENXP that he has no imagination and that everything s/he says is stale and repugnant would get a pretty fierce reaction methinks. Telling an ISXJ that they couldn't tell the difference between tert-butyl carboxylic acid and licorish would work better than telling them they are dull and unimaginative. They know that and recognise it within themself. Attacking Fi of an ISTJ might work though.
I reckon getting that reaction is key to manipulation of any kind. For example, you could get someone to play basket ball with you by telling them that they haven't done much excercise in ages and are starting to get hideously obese. If they are even slightly concerned about their weight they might be duped.
I'm thinking an attack on competence might work on anyone though? It might not be an MBTI related thing? I might as well try it on some people- trolllollollollol la lollololol!!!!