Of course it's a waste of time when someone consistently exposes the absurdity of your argument, repeatedly proving it completely void of merit, logic, and the most basic common sense. Quite annoying indeed. Don't know if I would resort to spitting and name calling... but that's just me.
.
oh, and just a tad of advice, ignoring is usually more effective when you're actually ignoring the person and not just talking about ignoring them - that completely defeats the whole purpose of ignoring. *-)