Green’s Dictionary of Slang

bottle of sauce n.

a horse.

1960		J. Franklyn Dict. of Rhy. Sl.
1984		Partridge DSUE (8th edn) 122/2: late C.19–20.
1992		R. Puxley Cockney Rabbit.
2002		K. Lucas ‘All my life I’ve wanted to be a Barrow Boy’ in Obfuscation News Apr. Issue 20 🌐 By the way, said Maurice, have you a Bottle of Sauce to pull the Smash and Grab. I presume you are going to be a Westminster Abbey with all your knowledge of the Joe Brown?