There are nagging questions and there are nagging questions. What do you do when, say, a friend calls you "chief" and you want to know if he's being ironic or not? Or if he even is a he? Just make your own interrogation room. It's a lot easier than you think!
1) The less room, the better. A classic beginners' mistake is to assume that you need to build a new room. Nope; the computer room is good enough. Just make sure your subject is blindfolded and cover the whole carpet with plastic floor mats. Or cover the plastic floor mats with rugs.
2) A mirror is important; two-way or one-way. You know how the suspect always cracks wise about how he knows the mirror is a one-way glass and he knows the cops are on the other side? Good; after you take the blindfold off, the suspect, deceived by the new floor mats, will think he's in a bona-fide interrogation room with a one-way glass. Deny it so he believes that the mirror is a one-way mirror. He'll never suspect the plush whale with a video camera on top of its head.
3) Get a spare chair and/or table. Throwing furniture is not as easy as it looks. Even after you avoid giving yourself a inguinal hernia or a slipped disk, you may still damage your chair. Sure you'll feel like Jack Bauer but you might not be able to sit down and enjoy the feeling after you break your swivel chair. So make sure to run to Staples and buy a simple folding chair and pick up a chrome dinette from wherever fine dinettes are sold.
4) Scopolamine is overrated. You might watch "24" and think that serums like scopolamine are necessary to win the war on error. There's a much easier substance that flys under the liberal watchdog radar: antique soda. Go on eBay and buy some old bottles of some obsolete beverage like Diet Rite or Crystal Pepsi. Then offer the suspect a drink. One sip of the flat, lukewarm soft drink will make him cough up the truth. Of course, threatening to inject the detainee with Tab will yield more results.
So all you need are plastic floor mats, a mirror, a folding chair, needles, a plush whale, a video camera, antique sodas and a chrome dinette and you can have your own private Gitmo. The only question your friend won't be able to answer is why you didn't do this sooner.