The souls of the just, however, can be helped by assisting in their purification.
REALLY?
2 Timothy 2:21
Therefore, if anyone cleanses himself from what is dishonorable, he will be a vessel for honorable use, set apart as holy, useful to the master of the house, ready for every good work.
Most believers, though in a state of sanctifying grace, still have some trace of the stain of their own sins on their souls, some attachment to sin, when they die. If you're like most faithful believers, you will die in God's friendship, freed by Baptism from Original Sin, but not perfect. That's why Scripture speaks so often of an ongoing purifying process: all that purifying of gold and silver provides us with an image of the purifying fires.
Not hell. The fire of Hell is not a purifying fire, mind you, because the damned never experience purity. That's permanent fire, and their goose, so to speak, is cooked.
But on the other hand, there are, as it is written, fires that purify. This is the promised purification of the just, the saved.