Green’s Dictionary of Slang

1. (Aus.) a whip.

1929

Sun. Times (Perth) 10 Nov. 65/8: I’m drivin’me Jack McNab down the field of wheat, an’ I makes a swipe at the applesauce with me egg-flip and I cops a pea over the dial.

2. (Aus.) a tip, information, usu. in horseracing.

1968		J. Alard He who Shoots Last 44: Dat’s wot I sez when I got da egg flip, but da vine sex he’s lookin’ hard fer ya.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 27: Egg Flip Tip (Information).
2002		Pete’s Aussie Sl. Home Page 🌐 egg flip: a tip, in horse racing.