My mother used to sing a variation of these lyrics. She was born in 1925, and I remember her singing this song when I was about 4 in 1955:
"Looking through a knothole, in grandpa's wooden leg,
I slipped and broke my eyebrow on the pavement.
Go get the Listerine, sister wants a beau,
But the beau's best friend is his mother."
Since I was about 4 or 5, "beau" could have been "bowl", and in the last line, "beau's" could have been "boy's".
However, what I thought I heard made/makes the most sense to me, and it's what still runs through my head.
I don't remember hearing any more lines to the song.
Very interesting reading the different lyrics that other people know.