Basically "Saadhana" word is not appropriate for this act. The spiritually developed practitioners attaining the stage of Aghora, use it for self examination of his energy. He brings some dead body, makes it purified, sitting upon it and transmits his own soul inside of that dead body and in the very position he performs hi "Jaap/Prayers" etc. Thus he confirms himself that the power of transmitting his soul, he has obtained. This is a hidden activity, not to be shown before anyone as a magician etc. By attaining the very energy Aghoris, Param Hansas or Aulias leave their body alive and travels universe to universe and could be able to present themselves more than one place at the same time or disappear instantly.