Behold the power of lecithin.
Oil tends to bead up when added to a hot pan or skillet. Commercial vegetable oil sprays, on the other hand, create a thin, even coating on cookware and bakeware because they contain lecithin, which forms a microscopic layer surrounding the sprayed oil droplets, helping them spread onto a surface instead of forming beads.
We heard that it's possible to combine liquid lecithin (available at health foods stores) and vegetable oil with an immersion blender and then use an oil mister to spray the mixture on cookware and bakeware to prevent sticking. Our mister clogged, but brushing the blended mixture (we used ¾ teaspoon of liquid lecithin and ½ cup of vegetable oil) onto pans resulted in easily released muffins and cakes and fried eggs that glided across stainless-steel skillets. Note: The lecithin in our homemade coating browned quickly, darkening the undersides of the eggs. This doesn't happen with commercial sprays since, in addition to oil and lecithin, they also contain an antifoaming agent that acts as a preservative, allowing its lecithin to be heated to higher temperatures without browning. We found that the darkening didn't affect the taste of the eggs, so if you don't mind the color, it's fine to use the homemade coating to fry them.
Source: Cook's Illustrated