He obviously did not read the thread, cages ogres is a good way to train range not prayer.
Best way to train prayer is right here.
Method A: (Fast but expensive)
Buy Dragon Bones
Use Dragon bones on guilded altar, you can find people with guilded altars on the RS forums and just go to their house.
Method B: (Low cost, slower xp)
Kill any dragon that will drop Dragon bones. Collect, bank and repeat until desired amount of bones is obtained.
Use Dragon bones on guilded altar, you can find people with guilded altars on the RS forums and just go to their house.
Those are the best methods for xp. Method 1 is clearly the best method to train prayer but you will need cash to buy the bones.