I normally use HTTP Mode (3rd party WEB server) together with the Embedded Mozilla Browser (and wonder how I managed without it!!)

Is there a way to switch off COOKIES in the embedded browser, to emulate visitors arriving with Cookies off?

You can invoke FireFox setting dialog for the embedded browser by clicking on the button in the browser's toolbar, left to the URL. Or open the list with appropriate chrome:// URL.

Thanks for that, I couldn't see it, and it was right in front of me.