Green’s Dictionary of Slang

popsicle n.

(US gay) the penis.

1988

H. Max Gay (S)language.

In phrases

on a popsicle stick (phr.)

(US) used as an intensifier.

1984

J. Ellroy Because the Night 205: ‘This fucker looked worse than the [...] walkin’ dead over there. He was righteous fuckin’ death on a popsicle stick.’.