Rubadubdub comes from Cockney rhyming slang and means 'pub' (Public House). A true Cockney is someone born within the sound of Bow Bells. (St Mary-le-Bow Church in Cheapside, London).
Some more Cockney expressions!
Here is a list of some Cockney expressions.
Adam and Eve - believe
all night rave - shave
apples and pears - stairs
Artful Dodger (Dickens' Oliver Twist) - lodger anyone paying rent
bacon and eggs - legs
bangers and mash - cash
Barnaby Rudge - judge
ball of fat - cat
bees and honey - money
bird lime - time doing bird means doing time in prison
Brahms & Liszt - pissed a common vulgar way of saying someone is drunk
brass tacks - facts
bread & honey - money
bricks & mortar - daughter
Britney Spears - beers
brown bread - dead
butcher's hook - look
Cain an' Abel - table
cat an' mouse - house
china plate - mate
darling daughter - water
dinky doos - shoes
Donald Duck - f * * k having sex
dustbin lids - kids children
Everton toffee - coffee
fiddle de dee - pee urinate
fish n' chips - tips
fourth of July - tie
frog an' toad - road
grasshopper - shopper shop someone also means to inform the police about a criminal
ginger ale - jail
Gregory Peck - cheque
half inch - pinch pinch is another word for steal and now in general use
hey diddle diddle - middle, or fiddle fiddle can mean to cheat with money
Joanna - piano cockneys would say piana rather than piano, so Joanna rhymes!
Jimmy Riddle - piddle piss, urinate
kippers - slippers
kitchen sink - drink
Lady Godiva - fiver a five pound note
loaf of bread - head commonly heard in English: Use your loaf!
mince pies - eyes
(Old) Bill - the police ITV’s police soap opera is called The Bill
Oxford scholar - dollar
plates of meat - feet
plink plonk - plonk commonly used in English as the word for cheap wine
pork pies or porky pies, or porkies - lies
rabbit and pork - talk the word rabbit is used in English meaning talk or talk too much
raspberry tart - fart make a rude noise from number 2 !
Roman candles - sandals
Rosie Lee - tea also flea
Ruby Murray a 1950's singer - curry
rub-a-dub-dub - pub the word pub is an abbreviation of public house
septic tank - yank British people use the word Yank for all U.S. Americans
sky rocket - pocket
Sweeney Todd a murderous barber in old London - The Flying Squad part of the police
tea leaf - thief
tiddlywink - drink
Tom & Dick - sick
trouble & strife - wife
Uncle Ned - bed
Vera Lynn a famous singer from World War II - gin