Respect or ridicule?

There is good reason to think that sometimes irrational beliefs can have negative consequences.
http://goo.gl/UCsxp
A common conviction is that the best way to handle disagreement is by adopting an attitude of patient and respectful dissent -- pressing gently for evidence or supporting reasons, and then following up by pointing out the inadequacy of the reasons provided.
A possible problem with this is that treating a hypothesis with respect may suggest that it is respectable.
It may be that in some cases, the best response is to dismiss the hypothesis as unworthy of serious consideration, and perhaps the way to do this so as to create the strongest psychological impact is through ridicule.