I have actually tried that in my own practice on various occasions. It almost never works, in my experience. In almost all cases, they deny they were pretending and insist that everything they have said or done is true/real.
Malingerers are basically pretenders and malingering isn’t exactly a mental disorder or a mental illness. Because it’s not a mental disorder or a mental illness, it can’t exactly be treated. But malingering could be as a result of an underlying problem. For example, someone who is fighting an addiction could malinger in a desperate attempt to get access to what he/she is addicted to. In that case, you treat the addiction to stop the person from malingering.
@Jonathan Samson Generally you only treat something that is medically wrong (e.g., and illness or injury). Someone pretending to be mentally ill to gain a benefit from it is not an illness or injury. They are simply pretending. There is no treatment necessary for that sort of behavior.
I would suggest to confront the person indirectly. Give the person who is malingering the chance to save face.
Malingerers are basically pretenders and malingering isn’t exactly a mental disorder or a mental illness. Because it’s not a mental disorder or a mental illness, it can’t exactly be treated. But malingering could be as a result of an underlying problem. For example, someone who is fighting an addiction could malinger in a desperate attempt to get access to what he/she is addicted to. In that case, you treat the addiction to stop the person from malingering.