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Nah, you need hygroscopic otherwise you're at risk of interstitial condensation, which is how you get damp or worse
See here https://ewipro.com/2019/01/15/why-choose-a-breathable-external-wall-insulation-system/
gillies
Isn't that the opposite of what you want? Materials that absorb moisture from inside the house and hold on to them sounds bad to me. Something that can get wet, and then dry out is OK (old school lime plaster and pointing etc).
Was in attic of a mates tenement last week, found the mineral wool put on the ceiling above what is now their bathroom was properly soggy. Has a new drop ceiling from the inside, left old on in situe, no vapour barrier, no other insulation, just the 300-450mm of mineral wool in the attic. Even in summer its wet with the moisture from the bathroom/shower passing up. All the lathe + old plaster underneath had fresh mould and wet to the touch (don't own a humidity probe thing). Also found their extractor that was fitted by factor's contractor a few years before just vents into the attic (in a different area) and doesn't go outside at all.