If you added the WaterWetter to the overflow, it will take quite a while to get into the radiator.
I used a turkey baster to remove as much coolant as possible (about 12 oz) at the cap.
Then I added 1/2 a bottle of WaterWetter and filled it back up with distilled water.
As long as I'm moving, I stay below 200 all summer.
In traffic, when the fans come on, rev the engine slightly to help the circulation and help the battery/fans.
Stay cool!