No. Why is that important? The cheap method is effective. Flushes the bottle of CO2, fill at a very low PSI, chill the bottles, and that's good. You still have to do that with a beer gun.Have you ever used a beer gun?
Obviously bottling for competition may require different rigor than heading out to a Christmas party for the night.
That's the point! The point is that the cheap method is just as effective as spending hard earned dough on a beer gun. You can flush the bottle with CO2 before you fill them, you don't need a beer gun! You don't!
Even if you didn't flush the bottles with CO2, if you cap on foam (which is almost 100% CO2), you won't have much O2 in the bottle if any.
You just can't always believe what you're told in ads and on TV. "You need this! Give us your money for something you can do yourself!"