I don't have personal experience with this problem but I have heard it discussed several times on our local handyman show. The answer seems to be that the only way to get rid of the odor is to "emcapsulate" the area using a product such as KILZ. It's fortunate that you will be recarpeting since the KILZ will certainly not match the wood. If the affected area goes to the wall be sure to take up the base molding and go as far under as possible. I have never heard another method mentioned that worked on a serious penetration. Good Luck!