CB, I can't stress enough how bad of a strategy that is. Mainly because you are wrong. If they do go through with it life doesn't go on, not for them anyways. And not for anyone else close to them who spends the rest of their life wondering why they didn't see the signs sooner. Anyone who wonders if they had just spent more time trying to help that person. For those people, for the family and friends who missed the signs, they live with a horrible burden the rest of their lives.
People who actually want to commit suicide are generally doing it because of pain. Because they are in so much pain, mental, physical, emotional that they don't see any possible way things can get better. They think they are a burden on the people around them, and that everyone they know would be better off without them.
Anyone who ever finds themselves talking to someone seriously considering trying to take their own life should try their best to convince the person they are talking to that they matter, that they make their friends and families lives better, and that they can get better, that they can get to a point where the pain will go away even if they don't see how now. And then once you have them even a little stable, you get them medical help immediately. Either driving them to a psychiatrist yourself or getting the police to do it for you.
But giving them any reason to think that people could get on without them, that they need to stop having a pity party, etc is completely the wrong thing to do. And before you argue that it worked, getting lucky does not make a bad strategy right.