The basket occasionally went in the dishwasher which cleaned the surface, but the well gunked grease has been building up.
Tried soaking the basket in soap and hot water. Scrubbing with a soft sponge. And then running the dishwasher multiple times but it only got a small part of the grease out.
Try this: slice a lemon in half. Put it in a heat-resistant bowl. Place bowl into airfryer and set at 200 Celsius for 20 minutes. It’ll probably smoke, so make sure to ventilate well.
After that, you may be able to wipe most of the grease away with a cloth.