When a phone is placed sealed in dry rice, it does absorb the water to a certain extent but then the rice gets damp, it then ferments gives off gases and causes more harm to the circuit board than the water ever could.
Either method is only going to dry the phone (or other electronics) but you can expect a failure down the line as even the purest tap water is full of containments.
A wash and dry in alcohol is the only trusted method.
•Immediately removed device from water, removed battery, removed SIM card
your device is essentially saved. You can dip any electronic device in water and if there's no power on the circuits, the only damage will be from corrosion. So long as you dry it out before that happens, it should be 100%. I guess you could start keeping all those little silica gel packets you get with everything, and then tear them all open and keep the good stuff in a ziplock bag, for that emergency.
Personally, when I get liquid on my electronics (it's usually a remote or keyboard), I yank power, attack it vigorously with a dustbuster to get rid of 95% of the moisture out the hard-to-get places, and then let the rest air-dry. So long as you get the big droplets out, the small films of water evaporate pretty quick themselves.
I don't think this product is a new "magic" product. As pointed out above, the CRITICAL factor is to remove power from the device - the quicker you can get the battery off the better. Then you can use a hairdryer, or open the phone up and let it sit in the sun.....just make sure you let it COMPLETELY dry fully before replacing the battery
I have a friend who puts his electronic devices in the kitchen dishwasher to clean all the dust/grime off. He then lets it dry thoroughly before applying power again. The trick is to insure there is no moisture in the device when you power it up again - ie patience
water does not damage electronics, it merely allows electricity to flow to to parts it shouldn't so the quicker you stop power to the device the better your chances.
Nowadays with newer tech more and more features are built in to the main processor so there a fewer components attached and fewer exposed circuits to fail, but if your processor goes no magic bag or no amount of rice will help.
With new tech developing hydrophobic coating, water damage will soon be a thing of stories and legends.