my two cents
I don't have the OCD thing with my ride. I run my cogs and chainring completely dry and keep my chain well lubed. I find lubing the cogs and rings causes buildup.
I clean my bike with water and two different size brushes only. Solvents remove the good as well as the bad, so never touch the stuff.
As for wear, I run my drivetrain for years without having shifting probs and I ride three days a week, but, when I do change drivetrain components I have to do everything, cogs, rings and chain.
That's my slack method, but it does seem to work. I definately clean her up after sloppy rides.