According to Osho, “entering another body” is an active, male technique: one vacates one’s own body and forcefully occupies another’s. Psychic mediumship is a receptive, female technique: the medium creates inner space and invites mainly bodiless spirits (like radio tuning) to enter, then dismiss them. Mediumship is simpler and safer; summoning embodied souls or forcible entry involves greater risk, including unconsciousness of the host.
It’s like the difference between breaking into someone else’s house and opening your own door for a guest—opening your door (mediumship) is easier and safer, and mostly lets in wandering spirits.