I find it hard to believe that we don't have the technology to chemically/electronically "debrief" anyone we might need to question without the use of "torture" as is is normally conceived. Efficacy, if not ethics, would seem to argue against most common ideas of physical torture.
There is no magic elixir. Different people have varying levels of tolerance against any of the "truth serums", which generally tend to lessen inhibitions and disorient them to make them more talkative. Just as some folks will tell all with only one or two beers in them, others can control what they divulge up to the point of passing out from a case of beer.
If you really want them to talk, you have to make the position of staying mum untenable...
the truth is that inmates will claim almost anything as 'torture' including loud noises in a prison environment that contribute to a lack of healthful sleep.
by electronic means I assume you mean lie detectors or voice stress analyzers. These are of varying use, depending on the language barrier and the amount of training someone has had on how to beat the machine.