While the barbecue is still warm, clean the grills with a suitable cleaning brush (available in e.g. the Boretti webshop). This makes it easier to brush off food residues from the grill and minimises the risk of mould. For the flat top grill, it is easier to use a spatula.
After the barbecue has cooled down, wipe the grill with paper towel or a cloth. This will remove the fine soot particles/fine dust from the grill and will thoroughly dry it. Next, rub the (cast iron) grill with a vegetable oil (e.g. sunflower oil or linseed oil). This prevents rusting and food residues burning into the grill during your next barbecue use.
We do not recommend cleaning the grills in the dishwasher, as this might lead to rusting. It is also really not necessary for a good clean result.