It's true that this expression is rhyming slang, but "bookies' rhyming slang" is not really a thing.
Bookies have a wide range of slang expressions, covering not only odds but lots of other things such as different types of punter. The only other example of rhyming slang that I could find was "beeswax" for betting tax.
Try here for an interesting selection of bookiers' slang terms (including beeswax), here for the most comprehensive list I found (how universal many of these terms are remains to be seen), or here for a comprehensive list of slang terms for various odds.
Some sources – such as the last of my three links above – treat bookies' slang as synonymous with 'tic–tac', but to my mind tic–tac is more about the hand gestures that bookies use to signal their odds across distances on the course.
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