Grave Sucking? Is that when someone sucks at a gravesite? What the heck can you suck there? ...I think I do not want to know.
See the link at post 1.
They are supposed to receive the spirit of the departed “saint”. It is a form of necromancy and definitely not biblical. Did Jesus or the apostles do any such foolishness? Whatever spirit they may or may not receive is most likely something similar to the demoniac among the tombs. The TV preachers and money prophets have brought this into the church. They false teachers use 2 Kings 13:14-21 as their proof text.