banana oil

Superfluous, disingenuous, or nonsensical talk, especially that which is meant to flatter someone or exaggerate something. Look, I know I won't get past the first round of this tournament, so you can stop feeding me banana oil.

Nonsense, exaggerated flattery, as in I should be on television? Cut out the banana oil! The precise analogy in this idiom is not clear, unless it is to the fact that banana oil, a paint solvent and artificial flavoring agent, has no relation to the fruit other than that it smells like it. Possibly it is a variation on snake oil, a term for quack medicine that was extended to mean nonsense. [1920s]

insincere or ridiculous talk. Like “horse feathers,” there's no such substance as banana oil. Also like “horse feathers,” the phrase Described something utterly preposterous. It has been attributed to Milt Gross, a cartoonist who first used the expression in his comic strips during the 1920s.