Getting a baby wet does NOT leave any kind of mark on their soul.
The Catholic church does not own my soul and any alleged marks that Catholics claim were there, have been washed off with the blood of Jesus who washed away my sin and took me out of bondage into glorious freedom in Christ.
I belong to HIM, being sealed until the day of redemption with the promised Holy Spirit who is the guarantee of my inheritance.
You are correct...it does, however remove original sin from the soul and initiate you into the church which Christ, Himself Personally founded..the Catholic church....No-one in the world has ever been validly baptized that didn't become a member of Christ's church....impossible.