Went for my weekly puja tonight, the Medicine Buddha Jang Wang powerful purification for the deceased. It's a special session for the deceased whereby the lamas will pray for those who have passed on, and bring and lead their conscienceness (spirit) to the Medicine Buddha's Pureland, so that they do not take rebirth in the lower realms.
My parents and niece attended the puja with me, because we were praying for my paternal grandparents as well as my maternal grandfather and his brother. The 8 lamas there conducted the puja and we brought along photos of my grandparents. At one point the lamas prayed and invited the spirits of the deceased into the place, and then by chanting prayers and burning the photos, they also called upon Medicine Buddha to lead these beings' conscienceness into his Pureland.
It's been about 30 years since my Ah Gong passed on and about 20 years since my Ah Ma passed on. I don't know if they have taken rebirth. But I guess this session at least will help transfer them into Pureland, if they have still not taken rebirth. At the same time for us living beings, it was a great way to purify our negative karma and deeds committed since beginningless time.