There are many old wives’ tales, but few are based on solid physical and chemical principles. Here are some tricks that no one has ever explained to you—and, most importantly, you’ll understand why they work so you can use them like a pro next time.

Why cut onions next to a lit candle? Many people wear glasses or chew bread, but a candle is scientifically the most effective.

Trick: Light a candle as close as possible to the cutting board where you’re cutting the onion.

Why it works: When you cut an onion, a gas (syn-propanediol S-oxide) is released, which, in combination with the moisture in your eyes, burns to form sulfuric acid. The candle flame draws in this gas and burns it before it reaches your face. Additionally, the warm air from the flame rises and carries irritants away from you.

Many people wear glasses or chew bread, but a candle is scientifically the most effective.

Trick: Light a candle as close as possible to the cutting board where you’re cutting the onion.

Why it works: When you cut an onion, a gas (syn-propanediol S-oxide) is released, which, in combination with the moisture in your eyes, burns to form sulfuric acid. The candle flame draws in this gas and burns it before it reaches your face. Furthermore, the warm air from the flame rises and carries irritants away from you. Why should you put a dry towel in the dryer with wet laundry?

If you want to save time and energy, this trick is unbeatable.

The trick: Put a large, clean, and completely dry towel in the dryer with your freshly washed laundry for the first 15–20 minutes.

Here’s how it works: A dry towel immediately absorbs much of the excess moisture from the wet clothes, thus reducing the overall moisture in the drum. This speeds up the drying process by up to 30%. Remove the towel after 20 minutes, otherwise the process will slow down.

Why should you shock eggs in ice water?

Sometimes eggs peel themselves, sometimes half the egg white comes off with the peel. The difference lies in the temperature.

Tip: Place the eggs in a bowl of ice water for at least 5 minutes immediately after boiling.

Why it works: The sudden temperature change causes the egg contents to shrink slightly, which loosens the inner membrane from the shell. This creates a microscopically small gap through which the peel literally slides off.

📊 Comparison: Common Sense vs. Scientific Trick
Problem Common Sense Home Remedies Why is it better?

Clogged kettle: Scrub with a brush. Citric acid + boiling. Chemically dissolves limescale without scratching.

Burnt pot: Soak for 24 hours. Boil water with apple peels. The acids in the peels dissolve the burnt-on food within minutes.

Dull scissors: Sharpening stone. Cut in aluminum foil. The foil gently smooths microscopic imperfections on the blade.

Why spray hairspray on zippers and ink stains?

Hairspray not only holds your hairstyle but is also a powerful solvent and lubricant.

Tip: If your zipper is stuck or you have an ink stain on your shirt, use hairspray.

Why it works: The alcohol in hairspray acts as an effective solvent, dissolving the color pigments from the fibers. On the zipper, the polymers in the hairspray form a smooth film that reduces friction.

💡 Final tip from “Peer”: Remove bloodstains with cold water only.

This is a rule few people know: Bloodstains can only be washed out with cold water. Warm water causes the proteins in the blood to coagulate, which makes the stain irrevocably bond with the fabric fibers. Cold water keeps the blood liquid, allowing it to be washed out.

Would you like to explain why ordinary chalk in a drawer containing silver prevents tarnishing?