After admitting to masterminding the 9/11 terrorist attacks, and after allegedly enduring waterboarding 180 times, Khalid Sheikh Mohammed asked his keepers at a secret CIA prison in Romania to grant him a special request. Mohammed, who has a bachelor's degree in mechanical engineering from North Carolina A&T State University, wanted permission to work on designing a vacuum cleaner, according to The Associated Press. And CIA headquarters approved.

As Adam Goldman at the AP tells it, the odd arrangement made perfect sense. About a decade ago, Mohammed had been interrogated and confessed to a career of terrorism. But the CIA wasn't sure what to do with him, and other key al Qaeda detainees, afterward. Knowing the prisoners' testimony might be useful in trials some day, the agency wanted to keep their minds and memories active. "We didn't want them to go nuts," as one former senior CIA official put it. So designing a vacuum cleaner actually seemed to be a worthy pursuit.

Mohammed, the AP says, set to work using schematics from the internet as a guide. His goal: To re-engineer a simple household appliance — like "an evil James Dyson," says Margaret Hartmann at New York.

Did he succeed? It's hard to say. The Romanian facility was shuttered in 2006, and Mohammed was transferred to the U.S. detention center at Guantanamo Bay, Cuba. He is still there, and Goldman says it is unlikely he was allowed to bring his blueprint and notes with him.

Mohammed's military lawyer, Jason Wright, says he has been barred from discussing the project. "It sounds ridiculous, but answering this question, or confirming or denying the very existence of a vacuum cleaner design, a Swiffer design, or even a design for a better hand towel would apparently expose the U.S. government and its citizens to exceptionally grave danger," he tells the AP.

The CIA says it can't discuss the details of Mohammed's effort to build a better vacuum cleaner — or even confirm his designs exist at all. The story is out, though, says Doug Mataconis at Outside the Beltway, so "if you happen to start seeing ads for the CIA's revolutionary new home cleaning device, you'll know where it came from."

In one way, though, it appears the project was a success. Military records suggest that unlike some other al Qaeda suspects interrogated for years, Mohammed has remained sane and healthy. In addition to the vacuum cleaner project, he was allowed to hold "office hours," talking to CIA officers in Romania about his childhood, family, and path to jihad, over tea and cookies. Mohammed also received Snickers bars as rewards for sharing information about al Qaeda, Goldman reported.

Mohammed also got to read books, the AP says. The Harry Potter series was a favorite. CIA officers once caught Mohammed trying to hide a message in a book warning other inmates not to talk about Osama bin Laden's courier. Were his blueprints some kind of trick, too? "It's not clear whether Mohammed was interested in designing a better vacuum or had ulterior motives," Goldman says at The Associated Press.

We might never know. "That the CIA may be in possession of the world's most highly classified vacuum cleaner blueprints," says Britain's Daily Mail, "is but one peculiar, lasting byproduct of the controversial U.S. detention and interrogation program."