Update: I've tackled this use case in this blog post - hopefully it will be helpful.
There is no clear form option available out-of-the-box available in the latest version of Aikau (which at the time of writing is 1.0.85). However, we did implement a related fix in version 1.0.81 following a community feature request.
We essentially added the ability to provide another button that doesn't contain the current form values, this allows a button to be added to the form that can publish the original values (so effectively clearing the form).
Thanks Dave for your solution..