Tom Boulding, landlord of Fagan´s Broad Lane Sheffield (a great session pub) has a version which included a chorus of "sinister dexter, sinister dexter".

And somewhere around verse four he would say:

Roman soldier goes into a bar and asks for a martinus.

Barman says "Don´t you mean Martini?"

"If I want more than one, I´ll tell you."

And with perfect timing as the laughter died down Tom would say:

"You can tell the ones educated at grammar school!"