While there is a certain attraction to the idea of being caught- the inevitability of punishment, the powerless feeling, and, of course, being able to pretend that if one had been just a bit more sneaky all of this unpleasantness could have been avoided, I find the concept of confession far more potent. It adds a layer to the psychology of discipline when one freely admits that it is needed. It is one thing to accept a punishment, but another entirely to request it.
The role of the authority figure is changed as well. Somewhat freed from the responsibility of rule-enforcement, more emphasis can be placed on guidance, on mentoring, and absolution. With no need for confrontation, a measure of sternness can be replaced with compassion- though not so much as to impede any due consequences.
Thinking of these things almost makes the confessing bit easier.