Scratch my back and I'll scratch yours.
Take a stick and scratch my back, please?
It's on the scratch-my-back-an'-I'll-tickle-your-elbow system.
[From The Atlantic Monthly, Volume 14, No. 85, November, 1864 A Magazine of Literature, Art, and Politics by Various]
Use me well, and I'm everybody; scratch my back, and I'm nobody.
[From How to Behave and How to Amuse A Handy Manual of Etiquette and Parlor Games by Sandison, G. H.]
Wipe my face, and I'm everybody; scratch my back, and I'm nobody.
[From The Handbook of Conundrums by Ordway, Edith B. (Edith Bertha)]
"You scratch my back and I'll scratch yours," is a kind of politics in which the reformer is no match for the boss.
[From A Ten Years' War: An Account of the Battle with the Slum in New York by Riis, Jacob A. (Jacob August)]
As you knock about, Miss Freeland, you'll find out one thing; all bigwiggery is founded on: Scratch my back, and I'll scratch yours.
[From The Freelands by Galsworthy, John]
They solved them on the plane of the proverbial lack of honor among thieves, by the formula, "You scratch my back, and I'll scratch yours."
[From The Making of an American by Riis, Jacob A. (Jacob August)]
"We're rich, we can afford a scratch-my-back-and-I'll-scratch-yours tariff that keeps our prices up arbitrarily, that takes fifty dollars out of your pockets to put in ours for every dollar it puts into the national treasury."
[From The Desire of the Moth; and the Come On by Rhodes, Eugene Manlove]