You may try this. Use an oilcan or oiler with hand operated squirter.. shoot some oil down the exhaust, try to get it down aways so you dont see it. When it gets hot, it will probably smoke a lot for a few minutes, then burn off..
I know this how?
one day oiling my chain, I idly shot a few squirts in my exhaust, I think 2 pipes of 4-4's. It actually did not burn off right away, but did when I was racing against a Triumph with a magneto on it.. He was CONVINCED I had blown my motor, or hurt it! Told him what I had done, he simply would not believe me...LOL..