I know a Taoist master who literally shut himself in a cave for many weeks just to practice going out of body to visit other realms. However his practice was rather ascetic, and he survived on half a glass of water in that cave while fasting for 49 days. He does talk about charisms, visiting "heavenly planes" and seeing other beings, and has also talked about his students seeing his body doubles. I'm not too sure how to explain body doubles though. He does not talk or brag about these things in the open which makes it difficult to find any writings or recordings, but these were heard behind closed doors.
His teachings usually revolve around firstly building the bodily life force elixir within the lower body, and then the upper body (heart and brow chakras). But more accurately, they don't use chakras as a term, the taoists use elixir fields (tan tien), of which there are three - one behind the navel, one in the chest, another in the third-eye. They also teach a successive cultivation, from life force to chi (energy), from chi to shen (spirit), of which we can then cultivate enough to traverse the universe in an 'immortal fetus' (aka the astral body)
