A person who dies without teshuva dies with a stain and goes to Gehinom.  They put detergents on him to get the stain out, and the detergents hurt… oooohhh de they hurt!  They burn! So the Neshama is somewhat scarred from his experience from Gehinom.  Therefore we shouldn’t wait until Gehinom in order to get rid of the stain.  Do teshuva while you’re still alive. ~ R’ Avigdor Miller zt”l