In other words, people will only convert for precisely the wrong reasons.
Absolutely true. If they were ready to accept the correct arguments, they would have become atheist on their own.
The probability for a given person to have developed a skeptical mind, have overcome the possible brainwashing effect of a religious education and all the possible correlated biases/fallacies (sunk-cost, belief-in-belief, etc.) and not having heard a compelling anti-religious argument is very low. Therefore, you can convert them either following the long, hard, but certainly more rewarding path of making them skeptical, if not rational, or you can bombard them with emotional nukes to demolish the emotional concrete walls that protect the religious belief.
In other, other words: People generally don't become skeptical until they realize they are really wrong on something really important to them.
Have you ever convinced a religious person to become atheistic? How did you do this? How long did it take? Were the people in some sort of life crisis, or were they just living along?
This is probably a quite difficult task of persuasion. So stories how people were successful at it could be very interesting to improve ones' persuasion abilities.
Relatedly, it might be interesting to know what religious groups have gathered on techniques to convert people to their religion - are there some manuals/techniques floating around?