People downplay such training, but imagine the environment without it. Imagine if nobody officially talked about corrupt practices: it would create a very dark place for such things to occur, nobody would know what the rules are or what to do, and especially the silence would speak very loudly.
Edit: By training everyone, not just the people directly involved with such situations, anyone considering corrupt acts will know that everyone - from the tech support person who helps them send the corrupt message to the receptionist who takes the corrupt call to the finance underling who mails the check - everyone will recognize it. There is no talking the rube into helping them; there are eyes everywhere, all the time.
Edit: By training everyone, not just the people directly involved with such situations, anyone considering corrupt acts will know that everyone - from the tech support person who helps them send the corrupt message to the receptionist who takes the corrupt call to the finance underling who mails the check - everyone will recognize it. There is no talking the rube into helping them; there are eyes everywhere, all the time.