if you wanted to only discuss LDS practice, do not open the door by making a comparison with Catholic practice unless you are willing to discuss it.
there isno door being opened to discuss RCC indulgences whenone makes a comparison, and even if it did, it does not detract from the lds theme because that is what is being compared. one just has to make sure tangents are thwarted and the discussion remains on the right track.

But to once again attempt to make indulgences more understandable, the real purpose of indulgences is not lessing the time of those in purgatory, as though it is some sort of commuted prison sentence. Although it may in fact cut the purgation time that one feels with that state.
the idea of RCC indulgences was to raise money for the church, the crusades and had little to do with any purity of heart. for the lds version, it has a lot to do with placating worried minds about loved ones and a quest to make everyone mormon, even without their permission.

the mere fact that either sects cold think that they have this power shows how deceived they really are as neither are taught in scriptures and both are then considered heresies or false doctrines.

that last bit is what you all need to worry about because if it is NOT taught in the Christian Bible then it should not be taught at all.