My bathroom mirror fogged up every single morning. I would wipe it with my towel, which just smeared toothpaste residue around, and then vaguely do my hair in a cloudy reflection. For years. Then I saw a hotel housekeeper do something weird with a tiny bottle of conditioner and a rag. She was not cleaning the mirror—she was coating it.

I tried it the next morning. My mirror stayed clear through a twenty-minute shower. I have not bought anti-fog spray since.

Why It Works

Conditioner contains silicones and fatty alcohols—the same ingredients that smooth your hair cuticle. When you buff a thin layer onto glass, those ingredients leave a microscopic film that prevents water droplets from forming. Instead of fogging up, the moisture sheets off in a thin, invisible layer. No droplets, no fog.

How to Apply It

Squeeze a dime-sized amount of any cheap conditioner—nothing fancy, the three-dollar drugstore kind works best because it has more silicones—onto a microfiber cloth. Buff it into the mirror in small circles, like you are waxing a car. Make sure you cover the entire surface evenly. Then take a clean dry cloth and buff it again until the mirror looks completely clear and streak-free.

The first time I did this, I used too much conditioner and my mirror looked like I had smeared lotion on it. Less is more. A tiny dab goes a long way.

How Long It Lasts

A single application lasts me three to four days before the effect starts fading. Reapply when you notice fog creeping back. One bottle of cheap conditioner will probably last you a year doing this weekly. Compare that to a tiny $8 bottle of anti-fog spray that runs out in a month.

This also works on car windshields—inside only, not the outside. I do the interior of my windshield once every couple of weeks during rainy season. Makes a real difference in visibility.

My bathroom mirror is always clear now. The housekeeper tip is still the best travel hack I have ever picked up.