In my schooldays, Liverpool kids had a tradition of 'one liners' - taking the innocent lines of songs and 'dirtifying' them
The rather beautiful, 'September Song' was represented as:
"The bits of brown came tumbling down in September" (a one-phrase alteration works wonders!)
Then the're's 'Rule Britannia', which emerged at the time of the Chinese Revolution
"Rule Britannia, marmalade and jam,
Five Chinese crackers up your arsehole
Bang, bang, bang, bang, bang".

That worked a bit harder at Funiculee, Funicular

Last night I stayed up late to masturbate,
It did me good, I knew it would,
Last night I stayed up late to masturbate,
It was so nice, I did it twice.

First I tried the long stoke
It was so grand with my right hand
Then I tried the short stroke
Was just as grand with my left hand

Swing it fling it, bang it on the floor,
Suck it, bite it, jamb it in the door
There are some people who may think that fornication is so grand
But for absolute perfection I prefer to use my hand.
My mother, who had a somewhat bawdy sense of humour', used to sing the parlour ballad, 'I Dreamed that I Dwelt in Marble Halls' with the line
"I dreampt I was tickling my old feller's feet,
With a glass of sweet oil and a feather,
The more that I tickled, the louder he laughed
'Till the cheeks of his arse flapped together"
Quite a lot more, if I can remember them
Jim Carroll