Ignorance is not a means of salvation. Most importantly, one cannot be saved without knowledge of Christ, since faith in Christ (who embodies all of God’s revelation) is necessary:
Catechism of the Catholic Church (CCC)
161 Believing in Jesus Christ and in the One who sent him for our salvation is necessary for obtaining that salvation.42 "Since “without faith it is impossible to please [God]” and to attain to the fellowship of his sons, therefore without faith no one has ever attained justification, nor will anyone obtain eternal life ‘But he who endures to the end.’"43
Following an upright conscience and seeking the truth puts one on the path to faith and salvation, but we must meet them on that path so that their desire may be fulfilled:
CCC (my bolding)
851 Missionary motivation. It is from God’s love for all men that the Church in every age receives both the obligation and the vigor of her missionary dynamism, "for the love of Christ urges us on."343 Indeed, God “desires all men to be saved and to come to the knowledge of the truth”;344 that is, God wills the salvation of everyone through the knowledge of the truth. Salvation is found in the truth. Those who obey the prompting of the Spirit of truth are already on the way of salvation. But the Church, to whom this truth has been entrusted, must go out to meet their desire, so as to bring them the truth. Because she believes in God’s universal plan of salvation, the Church must be missionary.
The following is also true:
848 "Although in ways known to himself God can lead those who, through no fault of their own, are ignorant of the Gospel, to that faith without which it is impossible to please him, the Church still has the obligation and also the sacred right to evangelize all men."338
Yes, God could just enlighten individuals directly and maybe He does at the “eleventh hour” in extreme circumstances, but because God is a communion of love (the Trinity), He has ordered salvation to be achieved in a communion of persons joined to Him and one another in faith and charity.
The Congregation for the Doctrine of the Faith recently released an explanation of this very point. The subsection entitled “V. Salvation in the Church, Body of Christ” is especially on point, but the whole thing is on this topic.
Finally, for those who have hardened their hearts to the small voice of God, many respond to the charity and word of another person–that personal interaction may be the way God brings that person to repentance and conversion. The Scriptures and history–and the testimony of many converts even in our time–show this almost always to be the case. Interior enlightenment is very rare. Most often, faith comes through hearing or reading the words of another and seeing and experiencing charity first hand.