I used to use all kinds of expensive chain lube products until I sat down and thought about what I was trying to achieve. With an O-ring chain, once the lubricant on the inside of each link dries out or is remove with a power washer or other means, it is gone forever. The O-rings will keep you from ever replacing the lubricant. The task then becomes adding a lubricant to the O-ring chain to ensure the O-rings do not dry out. Once I realize this, I switch to using WD-40 exclusively.
Now I spend more time on my bike than most folks (more than 5000 miles a year), so parts get a good workout. I use steel sprockets and O-ring chains, and usually get at least one year out of the set, so the use of WD-40 has not reduced the life expectancy of my chains at all. In fact, even with all of the miles, I have never broken a chain.
For my money (and very little of it indead), I just use WD-40. Now, if you are using a standard chain, we will have to have an entirely new discussion...
Rick