Should I change this old meta answer since it has some risky info (RE: CW posts)?
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Everything but the bit about the badge is either wrong or shady. Namely, you will get the reputation back if you perform a recalculation. Secondly, you shouldn't use Community Wiki to shield yourself from downvotes if your answer is wrong.
You should either edit the answer or (if you want the rep) add your own answer that correct's the first's bad information. (If it were me, I'd provide a new answer.)
I think that answer should be handled as any other answer given on an SE site.
You should not edit it, if you are going to change its meaning. If you think the answer is promoting something that should not be done, then you can down-vote it.