I've never experimented with lesser times, but chacruna *is* active boiled at the regular 3x3. My personal reasoning was always that, well, I'm at the stove and Caapi is cooking anyway...
I have HEARD that admixture needs as little as 3 x 30 minute boils, and freeze-thawing the leaves can hasten the process, BUT, I have never tried any of this myself. (Maybe someone else can chime in?)
Some things will come easy, some will be a test