Minor Description
If you don't wish to retain non delivered or expired persistent messages then it should be possible to easily disable the use of the dlq.
the discarding plugin will purge it, but that is not ideal.
Preferable is something like:
<destinationPolicy>
<policyMap>
<policyEntries>
<policyEntry queue=">" ..>
<deadLetterStrategy><discarding/></deadLetterStrategy>
...