Another nice sewer reference, so to speak, is in "The Maid of Cabra West":

So I follied him up to his lodgin's in Rathgar or thereabout
And as walked up an alleyway, I battered him inside out
He gave out many's the curse and swear - 'til he was dead, I'm sure
Then I lifted up the manhole lid, an' I thrun him down the sewer!

Regards