"A rehabilitation tool!?! LOL. More like a hit in the head with a shovel before kicking the body into a fresh grave. Excommunication deprives the person of the sacraments which Rome tells us are the means by which men are saved. No sacraments/no salvation.
But it's understandable some of us might be confused by the term. Just look at the pages and pages New Advent offers...
Since excommunication is the forfeiture of the spiritual privileges of ecclesiastical society, all those, but those only, can be excommunicated who, by any right whatsoever, belong to this society. Consequently excommunication can be inflicted only on baptized and living persons. Although the Church recites against the devil exorcisms in which the word anathema occurs, he cannot be excommunicated, for he in no way belongs to the Church. Among living persons, those who have not been baptized have never been members of the Christian society and therefore cannot be deprived of spiritual benefits to which they have never had a right; in this way, infidels, pagans, Mohammedans, and Jews, though outside of the Church, are not excommunicated. As the baptized cease, at death, to belong to the Church Militant, the dead cannot be excommunicated. Of course, strictly speaking, after the demise of a Christian person, it may be officially declared that such person incurred excommunication during his lifetime. Quite in the same sense he may be absolved after his death; indeed, the Roman Ritual contains the rite for absolving an excommunicated person already dead (Tit. III, cap. iv: Ritus absolvendi excommunicatum jam mortuum). However, these sentences or absolutions concern only the effects of excommunication, notably ecclesiastical burial. With the foregoing exceptions, all who have been baptized are liable to excommunication, even those who have never belonged to the true Church, since by their baptism they are really her subjects, though of course rebellious ones. Moreover, the Church excommunicates not only those who abandon the true faith to embrace schism or heresy, but likewise the members of heretical and schismatic communities who have been born therein. As to the latter, however, it is not question of personal excommunication; the censure overtakes them in their corporate capacity, as members of a community in revolt against the true Church of Jesus Christ. Catholics, on the contrary, cannot be excommunicated unless for some personal, grievously offensive act. Here, therefore, it is necessary to state with precision the conditions under which this penalty is incurred. Just as exile presupposes a crime, excommunication presupposes a grievous external fault. Not only would it be wrong for a Christian to be punished without having committed a punishable act, but justice demands a proportion between the offence and the penalty; hence the most serious of spiritual chastisements, i.e. forfeiture of all the privileges common to Christians, is inconceivable unless for a grave fault. Moreover, in order to fall within the jurisdiction of the forum externum, which alone can inflict excommunication, this fault must be external. Internal failings, e.g. doubts entertained against the Catholic Faith, cannot incur excommunication. Note, however, that by external fault is not necessarily meant a public one; an occult external fault calls forth occult excommunication, but in foro interno, as already seen. Most authors add that the offence must be consummated, i.e. complete and perfected in its kind (in genere suo), unless the legislator have ordained otherwise. This, however, is a rule of interpretation rather than a real condition for the incurring of censure, and is tantamount to saying that attempt at a crime does not entail the penalty meted out to the crime itself, but that if the legislator declares that he wishes to punish even the attempt, excommunication is incurred (cf. Const. "Apost. Sedis", III, 1, for attempt at marriage on part of clerics in major orders)......IV. WHO CAN BE EXCOMMUNICATED?
Yeesh.
I stand by my statement. It is used as a rehabilitation tool. Separating someone from the sacraments necessary for eternal salvation is a definite wake up call, the purpose of which is to bring the person back into the Church once they repent.
And I am sorry if the words were to big for you. *grin*