"One regular procedure . . . was making uncooperative prisoners strip to their underwear, having them sit in a chair while shackled hand and foot to a bolt in the floor, and forcing them to endure strobe lights and screamingly loud rock and rap music played through two close loudspeakers, while the air- conditioning was turned up to maximum levels, said one military official who witnessed the procedure. . . . Such sessions could last up to 14 hours[.]"
"The people who worked at the prison also described as common another procedure in which an inmate was awakened, subjected to an interrogation in a facility known as the Gold Building, then returned to a different cell. As soon as the guards determined the inmate had fallen into a deep sleep, he was awakened again for interrogation after which he would be returned to yet a different cell. This could happen five or six times during a night, they said."
http://tinyurl.com/7x7t7
The second procedure is pretty much identical to what Stalin's KGB used on the millions of innocent Soviet citizens arrested during the Great Terror, and invariably had the effect of making arrestees confess to crimes against the state THAT THEY HAD NEVER COMMITTED. Surely, Rumsfeld's people know this...and since people in this state will confess to literally anything, I don't know what kind of useful information they expect to get out of the detainees.