MessageQueue.Purge Method - Purge Contents a Queue
Purges the contents of a queue on a Message Queuing server.
If you are going to use this in an ASPX page you must ensure that the
application pool has permissions to perform this function. Full trust for the
immediate caller. This member cannot be used by partially trusted code. For more
information, see
Using Libraries from Partially Trusted Code
MSDN
Message Queue Class (Purge)
Try
'Connect to a queue on the local computer
Dim myQueue As New System.Messaging.MessageQueue()
myQueue.Path = ".\myQueue"
'Delete all messages from the queue.
myQueue.Purge()
Response.Write ("Purge Complete!")
Catch ex As Exception
Response.Write ("ERROR: " & ex.ToString)
End Try