I catch myself saying sarcastic and judgemental things all the time. Most recently after he'd done some grocery shopping: "Oh, you bought more milk" when there was already a full 3Litre bottle in the fridge (why didn't he just check beforehand?; why didn't I just shut up??).
And the detaching is still almost beyond me. But I have started to recognise how damaging it is for me to react emotionally to what he does. Maybe if you don't think of it as 'detaching' from him.... I try to think of how useless it is to get emotional with him. It really sets me/him/us back. So think of de-emotionalising rather than detaching if that helps at all.
And it's a great 180 to be calm, non-emotional and non-judgemental. Just notice, accept that's what he's done, and park it for later when you can get on here and post about it.
