You could pause consumption on the queues. In Weblogic JMS you can do that on the JMS Server, if you use those.
In AQ you can do dbms_aqadm.startqueue (https://docs.oracle.com/database/121/ARPLS/d_aqadm.htm#ARPLS113 ) where you set dequeue=false for the ip queues. Then afterwards call it again with dequeue=true.
Then enqueueing is possible, but the messages aren't processed. At my current customer we use a second set of queues and use OSB to move the messages back and forth. That way they can disable the particular proxy services.