MP initially used cold water, erroneously, with substance that absorbs excess moisture (6,6)

I believe the answer is:

talcum powder

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'substance that absorbs excess moisture' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.

'mp initially used cold water erroneously' is the wordplay.
'initially' indicates taking the first letters.
'erroneously' is an anagram indicator.
The first letter of 'used' is 'u'.
'mp'+'u'+'cold'+'water'='mpucoldwater'
'mpucoldwater' is an anagram of 'TALCUM POWDER'.

'with' acts as a link.

Can you help me to learn more?

(Other definitions for talcum powder that I've seen before include "A fine mineral" , "Bathroom preparation" .)

I've seen this clue in The Irish Times.

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