Medium chill is a little different for me than compassionate detachment, in that I'll use medium chill on people who don't really matter to me when all is said and done. Even family. The goal of medium chill is to simply be as boring and non-reactive as possible. It's not the silent treatment - I'm not ignoring the person - but any response I do give is as neutral and calm as possible. Another aspect of it is that not every comment has to have a response. Sometimes it's equally effective to let a couple of beats pass, so the person's clunker of a comment can just lie there, and then offer a change in subject. I'm also a big fan of pretending I don't understand hints/subtext, or didn't understand that I've just been insulted: "That dress makes you look less fat than the one you wore yesterday." gets "Thank you! ::big smile:: Oh, look at the beautiful weather. Such a pretty sky!" Or: "Oh, my friend's DIL/MIL/cousin is so wonderful - she takes my friend out to dinner every Wednesday." gets a smile and "How lovely!" The bottom line is that I don't have to defend myself, infer meaning, or argue back. Poor treatment really doesn't have anything to do with me, and everything to do with the person who gave it, so why should I treat it like it's relevant by responding to it?
Compassionate detachment to me is very similar, and is aimed at people I care about, where abandoning the relationship completely is not an option I choose to take. The big difference for me between compassionate detachment and medium chill is that I do initiate some contact, and I do occasionally make statements like "I recognize that you're angry about that, but I won't be shouted at." But for the most part, I again strive to be consistent, boring and nonreactive when attacked, even though I make slightly more effort to speak my piece in a calm and respectful way. I hold the relationship loosely, and accept that it might not be what I had planned, but it is what is.
I'm doing this with my son right now. He has a drug problem, so in between the large stretches of silence, I'll occasionally get texts or facebook messages that could be from angry DS, or high DS, or needy DS, or sad DS - never sure which. Some of them, I just let lie there and don't respond to. Some, I answer the explicit question and ignore the angry subtext (the passive aggressive or mean point behind the question). Some, I respond to honestly, or with a question. If it gets too bad, I'll say "I don't want to have this conversation while you're being so aggressive with me. If you can't be more civil, we need to stop now." and then if it continues I hang up or end the program. The governing concept here is "I love him, and we both deserve respect." The governing concept for medium chill, for me, is "not my monkey, not my circus" or "sometimes, people are just weird."
Don't know if that helped you at all, Shiny, but putting it out there just in case.