Nothing personal here and I'm not trying to insult you, but think about what you're proposing.
I also applied from Korea. I took all the documents to a lawyer's office. They arranged for a professional translator who was in the office next door. I dropped the docs off one afternoon. They were translated and notarized the next day. Cost: 300,000 won. Chances they will be rejected by CIC?; zero.
Your proposed method involves having your wife translate the docs. Her co-worker then checks it. Now the co-worker has to go to a lawyer or notary's office and swear an affidavit attesting to the accuracy of the translation. The translations have to be attached to the affidavit. I'm guessing you probably don't know how to prepare a Korean affidavit, so the lawyer or notary will have to do that. That's probably going to cost you 100,000 won. Chances it will be rejected by CIC?; who knows. If the translations are in fact rejected, you then have to have them professionally translated, cough up another 300,000 won and go back to square one of the process.
I suppose in the end it's your choice, but do you really want to roll the dice with your wife's visa application for the sake of 200,000 won? Given that the fee for submitting the application is going to cost you about 1,300,000 won anyway, I just don't see the logic in trying to do the translations on the cheap.