That is outright wrong.
The Catholic church has no claim to be the sole means or the claim to be any means of the salvation or sanctification of the believer.
God did not establish a religion of works to be made right with Him.
He had already set one up with the Law and the Jewish sacrificial system and priesthood. He abolished it. He didn't set up a new one.
We are sanctified by the Holy Spirit by faith, the same way we are saved, not through religious observances.
John 17:17-19 Sanctify them in the truth; your word is truth. As you sent me into the world, so I have sent them into the world. And for their sake I consecrate myself, that they also may be sanctified in truth.
Acts 26:14-18 And when we had all fallen to the ground, I heard a voice saying to me in the Hebrew language, ‘Saul, Saul, why are you persecuting me? It is hard for you to kick against the goads.’
And I said, ‘Who are you, Lord?’ And the Lord said, ‘I am Jesus whom you are persecuting. But rise and stand upon your feet, for I have appeared to you for this purpose, to appoint you as a servant and witness to the things in which you have seen me and to those in which I will appear to you, delivering you from your people and from the Gentiles—to whom I am sending you to open their eyes, so that they may turn from darkness to light and from the power of Satan to God, that they may receive forgiveness of sins and a place among those who are sanctified by faith in me.’
Romans 15:15-16 But on some points I have written to you very boldly by way of reminder, because of the grace given me by God to be a minister of Christ Jesus to the Gentiles in the priestly service of the gospel of God, so that the offering of the Gentiles may be acceptable, sanctified by the Holy Spirit.
1 Corinthians 1:2 To the church of God that is in Corinth, to those sanctified in Christ Jesus, called to be saints together with all those who in every place call upon the name of our Lord Jesus Christ, both their Lord and ours:
1 Corinthians 6:11 And such were some of you. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God.
Ephesians 5:26 that he might sanctify her, having cleansed her by the washing of water with the word,
1 Thessalonians 5:23 Now may the God of peace himself sanctify you completely, and may your whole spirit and soul and body be kept blameless at the coming of our Lord Jesus Christ.
Hebrews 10:10 And by that will we have been sanctified through the offering of the body of Jesus Christ once for all.
Hebrews 10:29 How much worse punishment, do you think, will be deserved by the one who has trampled underfoot the Son of God, and has profaned the blood of the covenant by which he was sanctified, and has outraged the Spirit of grace?
Hebrews 10:14 For by a single offering he has perfected for all time those who are being sanctified.
Hebrews 13:12 So Jesus also suffered outside the gate in order to sanctify the people through his own blood.
Try to find just ONE Catholic on FR that will DISAGREE with the following:
"One indeed is the universal Church of the faithful, outside which no one at all is saved, in which the priest himself is the sacrifice, Jesus Christ, whose body and blood are truly contained in the sacrament of the altar under the species of bread and wine; the bread (changed) into His body by the divine power of transubstantiation, and the wine into the blood, so that to accomplish the mystery of unity we ourselves receive from His (nature) what He Himself received from ours."
--Pope Innocent III and Lateran Council IV (A.D. 1215)
You did not even interpret what you quoted correctly which was “the FULLNESS of truth and the FULLNESS of the means of sanctification which are found only in the Catholic Church”.
It is explained several times in the article that “many elements of sanctification and of truth are found outside its visible confines”, that is in other non Catholic churches.