Green’s Dictionary of Slang

(orig. Aus.) chewing gum; thus chewie on your boot, a phr. used by barrackers at football matches in an attempt to put off a place-kicker by suggesting that he has chewing gum on his boot.

1960		J. Boswell Ernie and the Rest of Us 62: We demanded a bigger bit of ‘chewey’.
1962		K. Waterhouse There is a Happy Land (1964) 117: Got any chewy?
1975		A. Bleasdale Scully 99: A little piece of paper the size of a chewy wrapping.
1980		J. McClure Spike Island (1981) 33: ‘Have you put something back in your pocket there?’ ‘It’s just a bit of chewy.’.
1983		J. Byrell (con. 1959) Up the Cross 35: Ha ha ha ha ha to you, too. And chewy on yer boot‘’.
1990		T. Winton Human Torpedo 59: You could see them swapping chewies.
1996		J. Byrell Lairs, Urgers & Coat-Tuggers 31: [T]he gang treated Standish’s numerus modi operandi with the old chewy-onyer-boot [sic] treatment [ibid.] 197: ‘And chewy onyer boot. Because my brother-in-law Choko’s offered to train it for a whole year for essefay, man. And he says he won’t charge a zack.’.