Siempre le está dando jabón al jefe para conseguir un aumento.

[details=“English Translation”]He’s always buttering up the boss to get a raise.
[/details]

In this same collection, Spanish Idioms, we also have “le da coba”, with a similar meaning.

Wiktionary warns “Not to be confused with dar un jabón.”

https://en.m.wiktionary.org/wiki/dar_jabón