Jesus said, that he came to call sinners to REPENTENCE! pray a prayer does not talk about sin. Let me ask you a question.
Let's say your friend punched you in the face and later felt bad about it. What do you think his apology should be? 'I ask you into my heart, friend, because I did something terrible by punching you?' Nope, it wouldn't make sense. Instead of leading someone into a 'prayer' let them feel their sense of guilt by themselves and repent and trust. Otherwise we make the prayer a way to enter heaven.