Rule 19: Generalize the Matter, Then Argue Against it
Should your opponent expressly challenge you to produce any objection to some definite point in his argument, and you have nothing much to say, you must try to give the matter a general turn, and then talk against that.
Therefore, by labelling a specific position, for instance the belief that Dr David Kelly was murdered rather than committed suicide, as a conspiracy theory, and then pulling the focus back to conspiracy theories in general and lingering on those that are most outlandish or the easiest to debunk, such as the moon landings being fake or better still alien abduction, you can argue there's no point spending time dealing with the specific in question.
Rule 32: Put His Thesis Into Some Odious Category
If you are confronted with an assertion, there is a short way of getting rid of it, or, at any rate, of throwing suspicion on it, by putting it into some odious category; even though the connection is only apparent, or else of a loose character. You can say, for instance, "That is Manichaeism" or "It is Arianism," or "Pelagianism," or "Idealism," or "Spinozism," or "Pantheism," or "Brownianism," or "Naturalism," or "Atheism," or "Rationalism," "Spiritualism," "Mysticism," and so on. In making an objection of this kind, you take it for granted (1) that the assertion in question is identical with, or is at least contained in, the category cited - that is to say, you cry out, "Oh, I have heard that before"; and (2) that the system referred to has been entirely refuted, and does not contain a word of truth.
Even farther than that, 'conspiracy theory' has been so over-used, it has attained the power to induce an almost pavlovian response in some hearers, instructing them to file the contended information under 'dubious', 'dangerous' and 'probably nonsense'.
Rule 38: Become Personal, Insulting, Rude
A last trick is to become personal, insulting, rude, as soon as you perceive that your opponent has the upper hand, and that you are going to come off worst. It consists in passing from the subject of dispute, as from a lost game, to the disputant himself, and in some way attacking his person. It may be called the argumentum ad personam, to distinguish it from the argumentum ad hominem, which passes from the objective discussion of the subject pure and simple to the statements or admissions which your opponent has made in regard to it. But in becoming personal you leave the subject altogether, and turn your attack to his person, by remarks of an offensive and spiteful character.