Green’s Dictionary of Slang

(orig. milit.) cheese.

c.1943		S .J. Baker Aus. Vulgarisms [t/s] 7: bunghole: Cheeze [sic]. (Because of its constipating effect).
1965		F.J. Hardy Yarns of Billy Borker 25: Beautiful cheese—not like the bunghole here in Woolloomooloo.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 21: Bunghole Cheese.
1984		Partridge DSUE (8th edn) 157/2: C.20 military.
1986		R. Beckett Dinkum Aussie Dict. 12: Bunghole: Cheese.
1993		Aus. Word Map 🌐 bunghole Cheese; because of the unfortunate constipating effects of eating too much of it: I’ll just have a polony and bunghole sandwich, thanks.