With ad hominem and ad magazinam. If "method that works" means to you "method that works to convince someone", then there is anyway no difference to focusing on the topic. But if it means "method that works to find or clarify knowledge", then this is wrong. I genuinely wonder if the confusion of the two or trading the latter for the former may be at the heart of the problem, and if the rise of social media is training us to find the former the normal one. With all its stars and likes you get for ad hominem more than for a well done rational argument.