I do not believe there are any audit journal entries for message queues like there are for output queues.
I was going to suggest some auditing on the use of the command CLRMSGQ however I am not sure that the F13 and F16 in DSPMSG use this. A new user with limited capability can use DSPMSG and clear their message queue and any other they have access to. But you can try.
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Robert Berendt IBMChampion
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