I'm afraid I have to disagree with you on this one. After bragging about the murder of tens of thousands of innocent people, the only way Nathanson can wash the blood off his hands is with his own blood.
Sir or madam, What you say has a definite logic to it, but it's lacking. Nathanson's own blood could never cover over his murders. Only the blood of Jesus Christ, the sinless Lamb of God, can do that.