I understood from a priest that it's not actually as easy as it looks on paper. There is a "go and do that sin no more clause". (Not to be confused with approval with all other sins.)
It's not easy. It's never easy to do it right.
If nothing more, it brings home the fact that you can't do it alone!
That's true. And a plenary (full) indulgence can only be gained by a person who has cooperated with the grace of God in such a way that there is "freedom from the attachment to sin." That's pretty hard! Being merely in a state of grace is insufficient. Therefore, such a person (and that's probably most even attempting to gain an indulgence), gains a "partial indulgence" for the work at hand. Furthermore, our non-Catholic brethren might be open enough to see how *that* is pretty open-ended in God's favor! Since the indulgence is now "partial," and "partial" is not defined, it is up to *God* to decide what proportion to apply.
The pope and the bishops have control of the keys, but it's *still* God's house. Amen!