As I said, I use paraffin wax currently. I love the cleanliness and it just so happens to be the best performing both in longevity and efficiency. The only downside is the bits of wax that come off for the first 100 or so miles, but I can work on the drivetrain without getting dirty at all. Also, every time you re-wax it automatically re-cleans the chain without the use of any type of chain cleaner. And it doesn't collect grime. And it is cheap. And it easily lasts 500 miles without re-waxing. And it is the best performing. And to top that the efficiency actually improves over time.