Death always came after weeks of torture.
"Sometimes we would hang them upside down and beat their feet with clubs. Or we would electrocute them," he said.
"One of the worst things was putting 10 people in a one-square-metre room for weeks. They had a brief break every day and were allowed the toilet every three days," he said.
Three executions were carried out each Monday and Thursday. One day Saddam's feared son Uday showed up and asked about eight political prisoners standing nearby. He ordered their immediate execution, said Abu Hussein.
Abu Hussein, a father of three, said watching men writhe in agony as they died sometimes made him cry. But he said nobody could afford to defy orders in Saddam's Iraq.
"We would have been killed on the spot. One time this executioner was one hour late in hanging someone and he was himself hanged. What could we do? All of this had a toll on us," he said.
He sometimes broke the rules and allowed prisoners to inform their families of their whereabouts in the prison, which held thousands before their execution.
But the mention of Saddam turns him into a hard man prepared to torture and kill.
"I know they will set Saddam free. He is a strong man with a brain like a computer," he said.
Many of his fellow executioners fled Iraq after the 2003 U.S.-led invasion, fearful that prisoners or their families would seek revenge for their suffering at Abu Ghraib, now a U.S.-run facility also marred by prisoner abuse.
It is a black and white world, good or evil. And within each category it is all the same don't you know.