How to intentionally drop or flush the message queue when receiving "no free events for message"?

Whenever I do something to call on a Command or something, I would get large amounts of "no free events for message" warnings in the Console.

I know there are ways I can do to reduce this happening often by:

• Increasing the value in the "config.fragmentsize".
• Increasing the value in the "config.MaxSentMessageQueueSize"
• Decreasing the speed of how fast I'm sending out messages.

But point taken, it doesn't answer this question:

How do you flush / clear away / drop...

How to intentionally drop or flush the message queue when receiving "no free events for message"?