I also tried Badboy as i found it on another forum post. Badboy in my experience does not work. The issue with Mendix is the unique number that is generated each time a page loads. The URL is different each time so a tool like badboy or any tool that is looking for a specific URL each time will not work.
I believe in a future release of modeler v5 you will be able to set the page URL to enable this type of automated testing.
What may work to some extent which i have used is a mouse click recorder and replayer. this does not require specific url's and just replays your mouse movement and clicks on demand . We used this to test processes i.e. a questionnaire completion where the questionnaire had 50 questions.
The one I found that might work is Testcomplete. I have no experience yet and no time at the moment to check out the trial. But you can use this one for 30 days. So check it out and let us know :)
IMacros seems to work in a quick test.