Trick of excess verbiage - уловка лишнего словоблудия. Such tangents can be completely irrelevant or unnecessary, and they often make it hard to follow the argument. Some people even go off on tangents on purpose to confuse their opponents and hide gaping holes in their arguments. The irrelevant diversion is sometimes called a red herring (reportedly after a man who, when pursued by hounds, threw them off his scent by dragging a red herring across his trail).