How do I configure a automatic expiration for DLQ

1.For the dead letter queue ActiveMQ.DLQ, I would like to configure a policy
whereby messages in DLQ get deleted after they have resided in DLQ for 5
days.
I couldnt see how to do it in the documentation.
My current activemq.xml configuration file is below...how do I modify it for
autoexpiring my DLQ messages after 5 days...

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:amq="http://activemq.apache.org/schema/core"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://activemq.apache.org/schema/core
http://activemq.apache.org/schema/core/activemq-core.xsd">
<bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<value>file:${activemq.base}/conf/credentials.properties</value>
</property>
</bean>
<broker xmlns="http://activemq.apache.org/schema/core"
brokerName="localhost" dataDirectory="${activemq.base}/data"
destroyApplicationContextOnStop="true">
<destinationPolicy>
<policyMap>
<policyEntries>
<policyEntry topic=">" producerFlowControl="false" memoryLimit="1mb"
useCache="false">
<pendingSubscriberPolicy>
<vmCursor />
</pendingSubscriberPolicy>
</policyEntry>
<policyEntry queue=">" producerFlowControl="false" memoryLimit="1mb"
useCache="false">
<dispatchPolicy>
<roundRobinDispatchPolicy />
</dispatchPolicy>
</policyEntry>
</policyEntries>
</policyMap>
</destinationPolicy>
<managementContext>
<managementContext createConnector="false"/>
</managementContext>
<persistenceAdapter>
<kahaDB directory="${activemq.base}/data/kahadb"
ignoreMissingJournalfiles="true" checkForCorruptJournalFiles="true"
checksumJournalFiles="true" journalMaxFileLength="64mb" />
</persistenceAdapter>
<transportConnectors>
<transportConnector name="openwire" uri="tcp://0.0.0.0:61616"/>
</transportConnectors>
</broker>
<import resource="jetty.xml"/>
</beans>

2. What is the impact of adding the following plugin to the broker in
activemq.xml configuration XML
<broker xmlns="http://activemq.apache.org/schema/core"
brokerName="localhost" dataDirectory="$
{activemq.base}/data" destroyApplicationContextOnStop="true">
<plugins>
<discardingDLQBrokerPlugin dropAll="true" dropTemporaryTopics="true"
dropTemporaryQueues="true" />
</plugins>
</broker>