What's the best way to stop swim goggles from fogging?

The consensus across r/Swimming threads is that you should never rub the inside of the lens, which strips the factory anti-fog coating. Arena's Swipe technology (on the Cobra Ultra and Cobra Tri models) is repeatedly singled out as the one anti-fog system that actually re-activates with a finger wipe. Reviewers also mention diluted baby shampoo or dedicated anti-fog spray as cheap maintenance fixes.