No reason to oil the paint. Yes, some regular spray paints will start to come off from cleaning products. However, it is usually minimal and around the muzzle. If you use ceracoat or KG Gunkote I have not seen any paint wear from cleaning as they are baked on. Duracoat will show wear too, but it is not a bake on. Good thing is, if the paint starts to look bad just repaint it.