LOL!! The Holy Spirit gives us what we need to say and to say it at the right time. We don't know if Paul told the jailor anything more than what is written. Paul could have told the jailor a number of things. Do you think that any of it would have made a difference?
BTW-Why did this jailer fall down and ask what he needed to do to be saved while Peter's jailers (Acts 5) never repented after a similar situation and were executed? What was the difference?
So the question is, do those instructions apply to everyone? If your neighbor comes to you and asks "What must I do to be saved?" will you correct his errant soteriology and spend countless hours explaining the intricacies of Dortian Calvinism or will you simply reply, as Paul did, Believe on the Lord Jesus Christ and you will be saved?
I suggest that Paul's answer applies to every man that asketh.