First let me thank you for the excellent link.MAD King, I see looking at your other posts that you are from Germany? Welcome to the forums! "Dense-packing" cellulose is an installation procedure when insulating; http://www.karg.com/pdf/Insulaton_density/Dense_packing_Allwein_and_Biddle.pdf
It would help us in helping you if; you could explain why your interior walls need insulating. Is it for sound, to muffle noises/talking from one room to another? What is the sound source- stereo music, etc.? We need more information to help you reach the goal, but we need to know the "goal" first.