If you like, you can use cooking spray instead of brushing the oil on the cooking surface and the nuggets. But, just be aware that cooking sprays containing soy lecithin can cause a sticky buildup that may degrade nonstick surfaces over time. Here is an article with more info on how soy lecithin reacts with nonstick surfaces. If you want to avoid using soy lecithin on your air fryer but still like the convenience of a spray, look for a cooking spray without soy lecithin, or, use an oil mister.