I agree. Never let him in your home, car or any place where you are alone. If he happens to corner you at work, have nothing to say to him. That seems to discourge "most" men. I think we women do feel responsible for feelings and don't want anyone to suffer b/c of us, etc. If you have firmly told him your decision and he has no reason to doubt you, then you owe him nothing farther......not even conversation. Just look at him and say nothing and if he doesn't back away, then push past him and walk off! If that doesn't get the message, then you will have to resort to stronger methods.
Maybe b/c you have been too understanding and willing to listen to him cry on your shoulder is why he's take advantage of you. Be strong. You can do it.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!