Does this also apply to your own personal culture (whether aspiring or as-is), or “just” the broader context culture?
We’re talking about a tool for communicating with many different people with many different cultures, and with people whose cultures you don’t necessarily know very much about. So the bit you quoted isn’t just making claims about my culture, or even one of the (many) broader context cultures, it’s making claims about the correct prior over all such cultures.
But what claims exactly? I intended these two:
When you say, “In my culture X”, you’re also saying “In your culture plausibly not X”.
For some values of X, this will start fights (or hurt feelings, or sow mistrust, or have other effects you likely don’t want).
It seems like you came to agree with point #1, so I won’t belabor it further—let me know if I misread you and we can circle back. For point #2, I definitely agree that, the more charity the listener extends to you, the smaller the set of hurtful Xs is. But if you rely on that, you’re limiting the scope of this method to people who’ll apply that charity and whom you know will apply that charity. I picked “punishing the innocent” for my example value of X because I expect it to be broadly cross-cultural: if you go find 100 random people and ask them whether they punish the innocent, I expect that most of them will take offense. If you also expect that, you should build that expectation into your communication strategy, regardless of what your own culture would have you do in those kinds of situations.
Now, the better your know the person you’re talking to, the less important these warnings are. Then again, the better you know the person you’re talking to, the less you need the safety of the diplomatic/sociological frame, you can just discuss your values directly. That’s why I feel comfortable using all that highly absolutist “always/never” language above; it’s the same impulse that says “it’s always better to bet that a die will roll odd than that it’ll roll a 1, all else held equal”.
Thinking about it more, I suspect the real rule is that this method shouldn’t be used to talk about cultural values at all, just cultural practices—things that have little or no moral valence. That phrasing doesn’t quite capture the distinction I want—the Thai businessman who won’t shake hands with you doesn’t think his choice is arbitrary, after all—but it’s close. Another rule might be “don’t use these statements to pass moral judgement”, but that’s hard to apply; as you saw it can be difficult to notice that you’re doing it until after the fact.
I use this technique sometimes (my lead-in phrase is the deliberately silly “Among my people...”), but it has a couple of flaws that force me to be careful with it.
Most importantly, this framing is always about drawing contrasts: you’re describing ways that your culture _differs_ from that of the person you’re talking to. Keep this point in the forefront of your mind every time you use this method: you are describing _their_ culture, not just yours. When you say, “In my culture, we put peanut butter on bread”, then you are also saying “in your culture, you do not put peanut butter on bread”. At the very most you are asking a question: “does your culture also put peanut butter on bread?” So, do not ever say something like “In my culture we do not punish the innocent” unless you also intend to say “Your culture punishes the innocent”—that is, unless you intend to start a fight.
Relatedly, you have to explicitly do the work of separating real cultural practices from aspirational ones—this framing will not help you. When you write “In my culture we do not punish the innocent”, probably you are thinking something like “In my culture, we think it’s important not to punish the innocent”, since mistakes do still happen from time to time. But statements like “In my culture we put peanut butter on bread” do not require this kind of aggressive interpretation, they can just be taken literally, so your listeners might reasonably take “In my culture we do not punish the innocent” as a (false) statement of literal fact. Clear and open communication is unlikely to follow.
(If you feel like you grasp these points and agree with them, here’s an exercise: can the section of the OP that starts “In my culture, we distinguish between what a situation looks like and what it actually is.” be productively rewritten, and if so how?)
Overall, although I do like this technique and use it from time to time, I don’t think it’s well-suited to important topics. For similar reasons it’s easy to use in bad faith. That’s why I present it in such a silly and sociological (instead of formally diplomatic) way.