Okay, having done the above from memory. Here's the version from "Rugby Songs", or, according to the title page (rather than the cover) "Why was he born so beautiful" and other rugby songs.

Those old red flannel drawers that Maggie wore

They were tattered, they were torn,
Round the crotchpiece they were worn,

(Chorus) Those old red flannel drawers that Maggie wore.

They were hemmed in, they were tucked in,
They were the drawers that she was married in.

They were rotten down the front
With the dripping of her ****

She put them on the mat,
And paralysed the cat.

She put them in the sink,
My god there was a stink.

She hung them on the line,
And the sun refused to shine.

She buried them in the ground,
Killed the grass for miles around.