If I'm going to be doing an event type ride that I'm setting a bike up for, then here's what I do (right or wrong)

Remove the chain
Run it through one of my spin through brush type cleaners (those ones with cleaner in the reservoir and circle brushes), filled with simple green
Wipe it off
Soak the chain into a pan of 80-90 gear oil, leave overnight
Pull out the chain and let it hang, with the runoff going back into the pan
Wipe off the chain
Mount the chain

That method results in a chain that gets dirty quickly, but runs like buttah for several hundred miles.

If I'm not running an event, then I skip the oil bath and instead coat the cleaned chain with a chain wax (cleaner longer, but noticeably less smooth).