Tell us about yourself!
In a closed system, you would be right -- the heat that goes into heating and then vaporizing the water would be recovered when the water condensed and then cooled, warming the air around it. But the system you are interested in (your house) is *not* closed -- the heated and then vaporized water goes up the chimney, releasing all the nice heat it absorbed from your fire outside your house. So burning wet wood transfers heat from inside your house to outside ... not exactly the desired effect, at least in my house in the winter.
This is a great idea. Would be fun to do it with a 4" log/branch (cut in half to have a flat side. Wouldn't it be easier to do the joining with internal dowels (?) -- saves the trouble of plugs and leaves the outside natural (as it was) all around. Thanks for this.