No clean is done at all in this code in AxiomSoapMessageFactory and my experience too 
You can open a Jira for that.
You can easily extend the culprit AxiomSoapMessageFactory and add a deleteOnExit().
And the file will be delete at the shutdown of the sever (normally down in a lot of production environnement every time the server is restarted during the night).
Omar EL MANDOUR
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