When I read Philemon, it seems overwhelming tongue in cheek, like Paul is cheerfully goading his friend, Philemon. Here's the relevant part (with my comments in italics):
8 Therefore, although in Christ I could be bold and order you to do what you ought to do, 9 yet I appeal to you on the basis of love. I then, as Paul—an old man and now also a prisoner of Christ Jesus— 10 I appeal to you for my son Onesimus, who became my son while I was in chains. 11 Formerly he was useless to you, but now he has become useful both to you and to me.
Verse 8-9: I could order you but I'm strongly encouraging you to come to this decision yourself which you haven't so far without my intervention.
12 I am sending him—who is my very heart—back to you. 13 I would have liked to keep him with me so that he could take your place in helping me while I am in chains for the gospel. 14 But I did not want to do anything without your consent, so that any favor you do will be spontaneous and not forced. 15 Perhaps the reason he was separated from you for a little while was that you might have him back for good— 16 no longer as a slave, but better than a slave, as a dear brother. He is very dear to me but even dearer to you, both as a man and as a brother in the Lord.
Verse 12: he means everything to me (but don't let that influence you - you come to your own conclusion; no really, I mean it...)
Verse 14: (again) I really want you to come to this conclusion all by yourself.
Verses 15-16: yep, and I think God probably agrees with me as well.
17 So if you consider me a partner, welcome him as you would welcome me. 18 If he has done you any wrong or owes you anything, charge it to me. 19 I, Paul, am writing this with my own hand. I will pay it back—not to mention that you owe me your very self. 20 I do wish, brother, that I may have some benefit from you in the Lord; refresh my heart in Christ. 21 Confident of your obedience, I write to you, knowing that you will do even more than I ask.
Verse 18-19: sure, charge it to me, by the way did I mention you owe me everything?
Verse 21: yeah, you understand and you'll do even more, I'm sure of it (cough, cough).
22 And one thing more: Prepare a guest room for me, because I hope to be restored to you in answer to your prayers.
Verse 22: I'll be coming to check. You are praying for me, aren't you?
Is it just my reading of it, or is it written in a friendly but manipulative way, rather mischievously?