I've been practicing kuji kiri and then some specific GM Doo Wai school mudras for about 20 years on my own, in sitting and supine meditations
I will not get into my understanding of their working mechanisms, but as to their effects, they made me fit, energetic and my psychic potential improved.
I found them most useful getting rid of depression and lethargy, and kicking out my chronic bodily pains from their locations. (I am 63 now) But pains pop up somewhere else after a while so I haven't mastered them enough:-))
I feel very strong and invincible while practicing. They definitely work wonders and are a good path in spirituality. They are excellent teachers for serious solo practicers like me, and help manifest whatever the seeker has in the heart.
Good luck and happy practicing
