- What problem are you aiming to solve?
- What are the long-term options?
- What are the short-term options?
What's the problem?
Wrong answers will always exist. Always. We may wish it weren't the case, but the system was built with the assumption that they will come in. That's why the downvote button hover says:
"This answer is not useful"
Enough downvotes grey out a post and make it less visible. Downvotes also shift it to the bottom of the pile. And incorrect answers that have downvotes do provide value to SE (as much as we may dislike them) because they indicate to people looking for an answer, "This is not the answer you're looking for".
The problem with incorrect answers are when they provide a poor signal (they don't provide any value as a resource to people looking for an answer) -- this happens if an incorrect answer is not obviously incorrect, and the voting doesn't suggest it is incorrect (if it is equivalent in score to other more correct answers, or the only answer and not negative score).
If the answers in question are not going to be mistaken for the proper answer to the question by the people reading, I don't think it's a crisis that requires immediate attention either as a user or a mod. Voting and moving on is fine. That may be hard to do as a mod (especially when you see a pattern), but trust that the people reading have a brain and can properly grok the signal that the community has given on the value of the post.
Focus on the content, but don't ignore the user
Focusing on the content is usually the best way to become a good resource (users come and go, but hopefully your content will stay around forever), but if the user is actually the problem (in that they violate the guidelines in the help center regularly, particularly the parts about playing nice with each other), then don't hesitate to inform the mods (or as a mod, handle it appropriately by bringing it up with the user).
In the long-term, your signal should get stronger as more users come across the question/answer and vote. The better answers will move up, the incorrect answers will move down, and nobody will mistake an incorrect answer as the appropriate one for the question. So long-term this problem should get less significant so long as you put some effort in getting your community to vote early and often.
Our community was struggling with poor answers not getting downvoted, so our community discussed it on meta. Now we are pretty good with downvotes.
So long-term, this should resolve itself if you encourage your community and let it grow naturally. Take a look at some of the questions/answers from SO in 2008/2009, and you will notice that despite the issues people thought the site was facing then, time heals all wounds (and introduces new problems, like joint pain).
There are likely problems short-term with some answers giving a poor signal to people looking for resources, and acting as broken windows that can give a bad message to the community. These are the ones you should focus on (regardless of who posted them). In addition to a downvote, I encourage a friendly comment that will add to the signal rather than creating more noise:
Hey Wendi, could you clarify something on your answer please? You say that the proper answer here is to foo the bar, but this other resource says that you should foo the baz instead. Could you  your post to clarify the disconnect a bit better? Thanks in advance!
This will serve three purposes:
- It will clearly point out the objection with the answer and give the author a chance to fix it on their own
- Even if the person doesn't fix it, it will act as a clear statement explaining that not everyone agrees with the content of the answer regardless of voting
- It is assuming good-faith on the part of the answerer, using some 1920's psychology to inspire them to improve
If you have even more time, I would encourage writing a better answer and trusting that the community will upvote that in the long-term to make a clear signal even if/when your comment gets removed.