Currently there's an option in the sprinter to clear the database of an enviroment.
You have to stop the application, and the option 'Clear Enviroment' will became available.
It would be really helpful if clearing the database would be available by API (either the Deploy or Backups API). This way we can automate setting-up clean test data a lot easier. We use this data for automated testing.
We currently use a workaround: replacing the current database with an empty one using the Backup API.