he taints us all with his uttering
Why?
I don't think in the least that you (or this forum or whatever) is tainted in any way by allowing nonsensensical posts that then get refuted by people that know better.
As I said I can understand your frustration but nevertheless allowing nonsense to be uttered while unambiguously calling nonsense nonsense is the way to do it.
And just because you mentioned it: I live in a country where holocaust denial is not only censored - it is actually considered a crime.
However that does not bother the so inclined...
But I must admit that I don't vote at all when at least I should have downvoted some postings...