It’s a good question.
The Orthodox do not have a developed theory, a “one size fits all” theology concerning the deceased.
Certainly we don’t want them to suffer, if that is their fate. We will try to pray you out of Hell if that is necessary (yes, we will try… no guarantees). But there can also be the case that someone who is saved might attain a higher state of bliss, perhaps be closer to the eye of God. We just do not assume that there is punishment as such for any minor sins absolved in the confessional, but our prayers may be effective nonetheless. In other words one might rise to a higher state of divinization.
The biggest objections to the whole complex as formulated in the west is over the Anselmian Satisfaction Theory and the Thomist Treasury of Merits Theory. These were unknown in the early church, they popped up out of the scholastic era as explanations for Christian practice these men felt driven to rationalize. They almost couldn’t help themselves.

When these ideas were first introduced to Eastern bishops they were stunned.
Orthodox generally agree that when a sinner is forgiven in confession there is no other satisfaction (payment, or transaction) necessary. It’s done, no dipping into the Merit vault. One might be deservedly punished for something not sincerely confessed, but there is no residual payment due for something God has already forgiven through the practice of sincere confession and contrition.
If the deceased needs a good working over that is God’s doing, there is no system that can explain it. The more we try to explain it, the more likely it will be incorrect.
Think of this… going to meet your Maker is like going to your wedding, or a rare audience with the president. What would be the appropriate preparation for an event like that? Dressing up in fine cloth and jewels, fixing your teeth and styling your hair… or a sound bloody beating?
What is the process of salvation really like?.. hard labor in the mines, or a workout in the gym? Or is it neither? We just don’t know, for any person it can be different.
What we do know is prayer for the departed is good. We don’t reason out the why, we don’t need a theory and we don’t imagine a system. God does what God does, we are not going to box Him in and say “this is what God does and this is why He does it”.