Here are some Magisterial texts which support attaining eternal life without the character of sacramental Bapitsm...
Errors of Michael du Bay:
01031 31. Condemned Error: Perfect and sincere charity, which is from a "pure heart and good conscience and a faith not feigned" [1 Tim. 1:5], can be in catechumens as well as in penitents without the remission of sins.http://denzinger.patristica.net/#n1000
1032 32. Condemned Error: That charity which is the fullness of the law is not always connected with the remission of sins.
1033 33. Condemned Error: A catechumen lives justly and rightly and holily, and observes the commandments of God, and fulfills the law through charity, which is only received in the laver of baptism, before the remission of sins has been obtained.
Prior to this was the ecumenical Council of Basel, which was later translated to the Council of Florence:
Council of Basel, Session 22—15 October 1435:
The holy synod especially condemns and censures, in the book, the assertion which is scandalous, erroneous in the faith and offensive to the ears of the pious faithful, namely: Christ sins daily and has sinned daily from his very beginning, even though he avers that he does not understand this as of Christ our saviour, head of the church, but as referring to his members, which together with Christ the head form the one Christ, as he asserts. Also, the propositions, and ones similar to them, which the synod declares are contained in the articles condemned at the sacred council of Constance, namely the following. Not all the justified faithful are members of Christ, but only the elect, who finally will reign with Christ for ever. The members of Christ, from whom the church is constituted, are taken according to the ineffable foreknowledge of God; and the church is constituted only from those who are called according to his purpose of election. To be a member of Christ, it is not enough to be united with him in the bond of charity, some other union is needed. Also the following. The human nature in Christ is really Christ. The human nature in Christ is the person of Christ. The intimate cause that determines the human nature in Christ is not really distinguished from the nature that is determined. The human nature in Christ is without doubt the person of the Word; and the Word in Christ, once the nature has been assumed, is really the person who assumes. The human nature assumed by the Word in a personal union is truly God, natural and proper. Christ according to his created will loves the human nature united to the person of the Word as much as he loves the divine nature. Just as two persons in God are equally lovable, so the two natures in Christ, the human and the divine, are equally lovable on account of the common person. The soul of Christ sees God as clearly and intensely as God sees himself.So, clearly, catechumens can possess charity, and hence, be "members of Christ." This fact clearly resonates with that the Council of Basel also declared in the very same session:
Council of Basel, Session 22—15 October 1435:
These propositions and others springing from the same root, which are to be found in the said book, this holy synod condemns and censures as erroneous in the faith. Lest it come to pass that any of the faithful fall into error on account of such teaching, the synod strictly forbids anyone to teach, preach, defend or approve the teaching of the said book, especially the aforesaid condemned and censured propositions, and its supporting treatises. It decrees that transgressors shall be punished as heretics and with other canonical penalties. By these measures the synod intends to detract in nothing from the sayings and writings of the holy doctors who discourse on these matters. On the contrary, it accepts and embraces them according to their true understanding as commonly expounded and declared by these doctors and other catholic teachers in the theological schools. Nor does the synod intend by this judgment to prejudice the person of the said author since, though duly summoned, he gave reasons for being absent, and in some of his writings and elsewhere he has submitted his teaching to the church's judgment. Further, this holy synod orders all archbishops, bishops, chancellors of universities and inquisitors of heresy, who are responsible in this matter, to ensure that nobody has the said book and supporting treatises or presumes to keep them with him, rather he shall consign them to these authorities, so that they may deal with them in accordance with the law: otherwise let such persons be proceeded against with canonical censures.http://www.ewtn.com/library/councils/florence.htm
Prior to any of the above were the visions of Saint Catherine of Siena and Doctor of the Church:
St. Catherine of Sienna (14th Century): Dialogue of St. Catherine: Baptisms:
"I wished thee to see the secret of the Heart, showing it to thee open, so that you mightest see how much more I loved than I could show thee by finite pain. I poured from it Blood and Water, to show thee the baptism of water which is received in virtue of the Blood. I also showed the baptism of love in two ways, first in those who are baptized in their blood shed for Me which has virtue through My Blood, even if they have not been able to have Holy Baptism, and also those who are baptized in fire, not being able to have Holy Baptism, but desiring it with the affection of love. There is no baptism of desire without the Blood, because Blood is steeped in and kneaded with the fire of Divine charity, because through love was it shed. There is yet another way by which the soul receives the baptism of Blood, speaking, as it were, under a figure, and this way the Divine charity provided, knowing the infirmity and fragility of an, through which he offends, not that he is obliged, through his fragility and infirmity, to commit sin, unless he wish to do so; by falling, as he will, into the guild of mortal sin, by which he loses the grace which he drew from Holy Baptism in virtue of the Blood, it was necessary to leave a continual baptism of blood. This the Divine charity provided in the Sacrament of Holy Confession, the soul receiving the Baptism of blood, with contrition of heart, confessing, when able, to My ministers, who hold the keys of the Blood, sprinkling It, in absolution, upon the face of the soul. But if the soul is unable to confess, contrition of heart is sufficient for this baptism, the hand of My clemency giving you the fruit of this precious Blood... Thou seest then that these Baptisms, which you should all receive until the last moment, are continual, and though My works, that is the pains of the Cross were finite, the fruit of them which you receive in Baptism, through Me, are infinite..."http://www.baptismofdesire.com/BaptismofDesire.pdf
(Note that the above is a sede website!)