I don't think you need to buy a new plug unless you shoot powder in disc form. The older style plugs had a problem with crushing discs. I don't think you need to put any oil on the plug, it is stainless. Try spraying either carb cleaner or brake cleaner through the hole, before and after you use your pipe cleaner. You could use a number drill that is just barely undersize, (BY HAND), and that should take out anything that has built up. Just buy a cheap set of number drills an find one that takes out the buildup, just make sure you don't inlarge, or oblong ,the hole.