I don't have anyone on ignore although there are a couple of posters that I do skip over. My experiences have led me to believe the usual people that use the ignore tend to be the one's that make the most outlandish statements, can't back them up, and facts counter to their claims hurts their heads.
The whole problem with the world is that fools and fanatics are always so certain of themselves and wiser people so full of doubts. Bertrand Russell
You can ignore people without actually putting them on ignore. Just don't reply to anything they post. It is the best way to deal with a poster whose only aim is to be insulting or spout delirious nonsense.
You should never play cards with someone who is not dealing from a full deck.