There is nothing unique about the forgiveness of original sin at Baptism.
Baptism does not "forgive sins."
We are saved by Christ's sacrifice on the cross.
But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness." -- Romans 4:4-5 "Now to him that worketh is the reward not reckoned of grace, but of debt.
Men carry the stain of original sin all the days of their life.
And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith: That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death; If by any means I might attain unto the resurrection of the dead. Not as though I had already attained, either were already perfect: but I follow after, if that I may apprehend that for which also I am apprehended of Christ Jesus." -- Philippians 3:8-12"Yea doubtless, and I count all things but loss for the excellency of the knowledge of Christ Jesus my Lord: for whom I have suffered the loss of all things, and do count them but dung, that I may win Christ,
But if a man is born again by the Holy Spirit, Christ will cover that stain with His own righteousness.
"She is not afraid of the snow for her household: for all her household are clothed with scarlet." -- Proverbs 31:21