The ovens are largely self-cleaning due to the high temperatures that they reach, making maintenance very simple. Any bugs and bacteria will be killed off by the high temperatures, and for any hard-to-remove stains you can use a damp – not wet – cloth to remove them. Other than sweeping out the ash after use, no further cleaning is needed, although the flue will require cleaning occasionally, which can be done using a flue brush.
If you haven’t used your oven for a while it is worth starting a fire and allowing it to slowly reach a high temperature to ensure that it is clean before you start cooking with it again.