Green’s Dictionary of Slang

polish n.

1. [1900s] (US) a fool, a synon. for shine n.2 (3); a failure.

2. [1900s] effrontery, arrogance.

3. [1980s+] (N.Z.) fellatio.

4. [1990s+] an act of masturbation.

SE in slang uses

In phrases

boot polish (n.) [which is black]

[1950s] (UK Und.) blackmail.

brown polish (n.) [late 19C–1900s] (orig. US)

a person of mixed race.

In compounds

nose polish (n.)

[1910s] (US) alcohol.

shoe-polish (n.) (also furniture polish)

[1900s] (US) whisky; thus shoe-polish shop, a saloon.