Green’s Dictionary of Slang

shine-rag n.

In phrases

win the shine-rag (v.) (also win the shiney rag) [? one is thus reduced to cleaning shoes for a living]

to lose one’s money by gambling.

1859		Hotten Dict. of Modern Sl. etc. 91: ‘To win the shiney rag,’ to be ruined.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor I 18/1: He lost again, and some one bantering said, ‘You’ll win the shine-rag, Joe,’ meaning that he would be ‘cracked-up,’ or ruined, if he continued.
1861		Melbourne Punch ‘City Police Court’ 3 Oct. 234/1: Prisoner.– Your honor, I’ve won the shiney rag, now, and mayhap shall get sevenpen’north, so Don’t be hard upon a cove as is in for patter.
1873		Sl. Dict. 286: Shiney rag ‘to win the shiney rag,’ to be ruined, ? said in gambling, when any one continues betting after ‘luck has set in against him’.