I'll withhold my opinion of devices like this as it would only add insult to your current injury.
Having said that, why would you have to dump a keg that was taking time carbonating? Let it sit on gas until it's ready!
My method when in a rush to serve:
Set gas to 25psi, place the keg on it's side and rock it back and forth for a few minutes then place in the fridge for 24-48 hours, turn off the gas, burp the keg to release pressure, replace gas line and set to serving pressure.