Suggestion: Have an old plug that you use as your “after run oil plug” Use it when starting for the first time after using after run oil. Switch to a “good” plug after the oil is burned out of the cylinder. That way, you don’t have to worry about fouling a “good” plug. After a new plug has several runs on it (before its worn to an unsafe limit!
), it becomes your “after run plug” and so on.