To do 'The Dirty Guinness' one must down one's pint of Guinness then continue to thrust said empty pint glass into ones face, shattering it in the process.
Paddy O'Halloran: I can't make it into work today boss.
A person you hate intensely not because they deserve such hatred but because they serve as a focus for your general hatred. A healthy way to dispense with excess animosity.
Jake's not really that big an asshole. He just serves as my hate sink.