The Topic title actually says it all. I think scathing tirade is a powerfull skill but as said somewhere else it needs to well played. You have to act out the tirade and the GM could grant the roll. I don't think the roll should be granted without any spoken word by the PC.
It can't be just the dice it needs a story and the PC needs to bring it convincingly.
My question here is....What would you say to convince the GM to grant the roll?