With the recent success of large language models, the idea of AI-augmented Business Process Management systems is becoming more feasible. One of their essential characteristics is the ability to be conversationally actionable, allowing humans to interact with the system effectively. However, most current research focuses on single-prompt execution and evaluation of results, rather than on continuous interaction between the user and the system. In this work, we aim to explore the feasibility of using chatbots to empower domain experts in the creation and redesign of process models in an effective and iterative way. In particular, we experiment with the prompt design for a selection of redesign tasks on a collection of process models from literature. The most effective prompt is then selected for the conducted user study with domain experts and process modelers in order to assess the support provided by the chatbot in conversationally creating and redesigning a manufacturing process model. The results from the prompt design experiment and the user study are promising w.r.t. correctness of the models and user satisfaction.