擦油泥

cāyóuní ㄘㄚ ㄧㄡˊ ㄋㄧˊ

    • to clear away outdated, unrealistic ideas and ways of thinking

Character by character

Saying俗语俗語

Idiom惯用语 · Rarely used now

Literally
wipe off the oil sludge
Meaning
To clear away outdated, unrealistic ideas and ways of thinking. Neutral, a bit bookish.

Sources