Green’s Dictionary of Slang

flattery, insincerity.

1884		‘’Arry at a Political Pic-Nic’ in Punch 11 Oct. 180/1: The palaver was sawdust and treacle. [...] Fancy, old chump, Me doing the sawdusty reglar, and follering swells on the stump.
1885		‘’Arry on Song and Sentiment’ in Punch 14 Nov. 229/1: That’s larks, that’s true poetry, ain’t it? Not sawdust and snivel, no fear!
1887		Fife free Press 29 Jan. 2/1: If a man is bursting to benefit a locality let him do it without all the sawdst and brass-hand business.
1899		Dover Exp. 17 Feb. 7/5: There seem to be two kinds of pride — one that blows itself up with wind, and the other that fills itself up with sawdust.