The way I see it, socionic phenomena will happen whether you believe in it or not. Knowing socionics just helps you recognize them and be aware of them. Despite that though, I'm sure I still miss socionic-based events, which is fine of course. I feel socionics is best used as an observational tool rather than something you can use to manipulate situations.
However, case in point, socionics has come in handy for me in dealing with an Se-POLR, Fe-DS coworker who was spreading false vicious rumors about me at work. When, in the heat of the moment, I was going to respond to her in an Se-ish way (i guess recruiting my role function), threatening to sue her for slander, I decided against that course of action (and i'm really glad i did). I ended up deciding to sit down with her and talk through everything, bring everything out into the open and debunk the lies she was telling. It worked really well, but I did make her cry towards the end of the discussion (once the fact that she was lying was made obvious), at which point i remembered she has Fe-DS, and I gave her a hug (which worked like a charm). Now we are back to being "friends", though I will NEVER trust her again (I actually never did trust her, even from the outset, but now i trust her even less). I have to say, knowledge of socionics was, in part, what guided me in resolving this challenging situation in a relatively benign way.