When there is a large number of integration messages to remove from the WebSpere queue, it is quite helpful to do a mass deletion of the messages, especially if the queue is stuck because of the threshold of messages being reached.

One way to remove the messages is using wsadmin tool in WebSpere, like below:

set id [$AdminControl queryNames type=SIBQueuePoint,name=<queueName>,*]
$AdminControl invoke $id deleteAllQueuedMessages false

This method to remove the messages is fast as well.

There are other ways to remove queues from WebSphere, either from the External Systems application in Maximo, or from the WebSphere console, documented here: https://www.ibm.com/support/pages/deleting-non-processed-messages-queues-%E2%80%93-mif-maximo-integration-framework.

Another way is using the deletequeue.cmd from the administrative folder of Maximo, like documented here: https://www.ibm.com/support/pages/cannot-delete-messages-continuous-queue-deletequeuecmd.