I saw an improvement within the first oil change. This is not a miracle cure, as those things don't exist. This was just a little puff that indicated very mild wear and/or hardening. If a seal has degraded significantly, it has to be replaced. If you blew out your rear main seal by overfilling the crankcase, the seal has to be replaced.
The reason anyone is ever looking for a miracle automotive cure is because they ignored something while hoping it would go away on its own. Turning up the radio doesn't really make that noise go away.