What is a "waterboard"? Where is Hussein's waterboard confession? Does his confession match that of the "mastermind"?
Even trained CIA operatives cannot last long under this sort of interrogation. Ramzin binalShib lasted about 30 seconds. Khalid Sheik Muhammed lasted about 90.
As far as Saddam Hussien is concerned, I'm not aware that he was ever interrogated using this technique. Since was an enemy Head of State, he would be treated to Geneva Convention protection.