Taken 3, Bryan torturing Stuart. What kind of torture is that?

The director of the film, Olivier Megaton has explicitly confirmed that we're witnessing "waterboarding", a torture technique intended to simulate drowning

Per wikipedia:

Waterboarding is a form of water torture in which water is poured over a cloth covering the face and breathing passages of an immobilized captive, causing the individual to experience the sensation of drowning. Waterboarding can cause extreme pain, dry drowning, damage to lungs, brain damage from oxygen deprivation, other physical injuries including broken bones due to struggling against restraints, lasting psychological damage, and death. Adverse physical consequences can manifest themselves months after the event, while psychological effects can last for years.

Interestingly, he claims not to have known that the CIA was using this at Guantanamo Bay while they were making the film.

Megaton : Unconsciously I’m doing this, but I don’t think about it when I’m doing the movie. When you read the first script, it had “Fuck” everywhere but we are not making the kind of movie where you need to have a fuck every page. I just removed too many things that would make trouble for me later. Another example, there’s torture at the beginning of Taken 3, a corkscrew, I said it’s not possible. They’re always very strict on torture. We found instead that an ex CIA agent could use waterboarding. After filming we found that the CIA had used waterboarding a lot in Guantanamo, so that caused problems anyway.