Yes it works, I had a jazz hybrid courtesy car last week and gave that a shot.
switch the multi information screen to the graph that shows where the power is going to,
say like when you are cruising along at 30mph, ease off the gas pedal very slowly then you'll see arrows from the engine to the car disappear, and with only the arrow going from the battery to the car.
I believe this is when its running on electric only. (the engine is not switched off, just the fuel cut off i think and engine kept running by the movement of the wheels)
but if you fully take you foot off the gas pedal, then the arrows between the car and battery will go the other way, from car to battery, in which case i believe it's charging the battery.
So have to keep a very slight pressure on the gas pedal