I would even say, CBT in its general sense, cognitive + behavioural does the same thing, however; whilst stress inoculation is part of CBT, many don't use it, and the BIG difference, is that DBT focuses more time on emotional stability than normal CBT, because this is where those with personality disorders fall apart, the moment they begin reviewing their trauma. This extra time on emotional stability is in order to aid them during the trauma processing aspects of therapy. It would not be uncommon that a severe case in the complex trauma range spend 12 months alone on emotional stability, behavioural stability, self esteem building, etc... before hitting trauma therapy itself; again, depending on the severity and attitude of the person.
I would say this is where most trauma therapist really run out of time... because it is quite a full-time role to get a personality disorder emotionally stable with rational thinking when placed under significant distress when faced with trauma therapy. Even then, most still fall apart and forget most of what they learnt... and have to be heavily reminded, baby sat even, to ensure they focus on their emotional stability after being duressed.
Personally... I don't think a 2 or 4 week program could effectively teach a person with trauma + personality disorder, effectively enough to manage when pushed by a therapist to face their trauma. The majority would still fall apart. It is always a good start though, and if the person does the right thing afterwards, being to practice, practice, practice, that would significantly help then.
I would say that most of the people I have done one on one help with over the years here, have been complex cases, and every single one was significantly time consuming for a good 3 - 6 months of my life, daily, multiple times daily, or every 2-3 days minimum, some form of contact and reassurance was required. Obviously during the worst stages, multiple daily support is required to a person enduring trauma therapy.
Its not anyone's fault... its just the nature of complex trauma. The worst the childhood trauma, the harder the fallout usually, ie. suicidal behaviour, self harm, destructive behaviour, etc. If you get someone who can devote that sort of time though, usually a person with complex trauma can be significantly better within that time frame... massive improvement.