Use the forum search feature and the keyword interrogation. Although the discussions are more general than specific, due to reasons that David mentioned, there is commentary and links that are useful.

I will say that your second-hand comment:
....stress positions and sensory deprivation were the only way to get actionable intelligence from bad guys.
...is completely untrue, and whoever stated such nonsense is an amateur treading along the path to criminal action.

Second, as a cherry 35M, you need to seek out experienced NCOs and Warrants for advice and mentoring. They won't come to you - it needs to be the other way 'round.

I also recommend that you get on BCKS MI Space, specifically the HUMINT & CI area, and look through the material and post any RFIs you may have. (Access requires AKO log-in) Discussion can be a bit more open in that forum, but although it is relatively secure compared to an open board it is still an unclass forum with limits to how far you can go on that subject.