"First catch your hare" as Mrs Beeton put it. And how'd they'd ever know they'd got the real one?

No the simpler thing would have been to announce publicy, so that the Iraqi people could hear it "We can now asure you that the bastard hasn't got any poison gas. And if he puts any helicopters into the air, we'll promptly shoot them down." And then sit back, and get ready to make friends with a fairly radical, but popular regime, made up of Iraqis who hated Saddam, but didn't trust outsiders too much either.