Normally I like voice commands, but I'm not sure I see any advantage in this case.
To use a voice command, you would use your right thumb to press the voice command button, wait for system response noise. Speak the command, wait for it to be recognized and then the washer/wiper would cycle.
As opposed to how it does work, which is to use your right thumb to press and hold the windshield wiper button and it sprays the windshield almost instantly and will keep spraying as long as you hold the button down.
Once you let go it gives a few more wipes, waits a second or 2 then gives one more wipe to get the drips.
How you press the wiper button changes how it responds.
A quick press cycles the wipers once.
A long press triggers the washers and 3 wiper cycles.
Press and hold continues to wash as long as you hold the button down.
Any press of the wiper button also gives you time to use the left scroll wheel to change the wiper speed or select auto.
The amount of time this stays displayed was increased with a recent ota update.
Same thumb different button and an almost instant response that keeps washing as long as you hold the button down. Why would you want a voice command for this function?