I don't think nonsense should be ridiculed for what it is, because "nonsense" is subject to perception, no matter how stupid that persons perception may seem to us we're not them. After all in the words of Willy Wonka "A little nonsense now and then is relished by the wisest men".
I think it's better for people to present their case, draw their own conclusions, and then find ways to co-exist without infringing on each others beliefs or trying to force them on each other. Mind changing should come naturally with education, open thought and discussion, and freedom. Not through shame, ridicule, force or any other negative action.