The sooner we get behind this, take our lumps and move on, the better. Bush can focus on Saddam's capture and the liberation of 26 million people... If he waits until closer to the election, it'll be a slow trickle that just won't go away, and in the end, it could seriously destroy his credibility.
All he would have to do is get a bunch of prisoners to construct and/or modify the hiding place. and load it with the WMD. Then execute them.
Then, execute all the scientists and workmen that could possible know their whereabouts.
Or do you suggest Saddam Hussein is above that?