Manufacturers just love to helpfully instruct us on how to use their products. Some directions are painfully obvious, such as the packet of peanuts that reads, “Open packet, eat nuts.” Some instructions are silly, like the bottle of Nyquil that cautions, “Warning: may cause drowsiness.” Then there’s the warning on my new iron: “Do not iron clothes on body.” Umm, what?
Some instructions seem like they’re made to be ignored, especially subjective instructions about how much of a product to use or how often to replace it. How do we know if something really needs to be tossed out every few months, or if its expiration date is set in stone? When manufacturers make these recommendations, are they thinking about what’s best for the consumer, or are they just thinking about what’s best for their bottom line?
Lather, Rinse, Repeat?
Is there really a reason to wash twice? Is the product so ineffective that it can’t clean properly the first time? The reality is that you only have to shampoo once. According to CNN Money, the “rinse and repeat” instruction came about in the 1950s, when people washed their hair less often and used heavier, stickier hair products. Sometimes, the first shampoo wouldn’t generate suds because of all that oil and Brylcreem, so a second wash was necessary in order to work up a lather. Shampoos don’t actually need suds to work, but companies know that customers like to feel as if they’re really getting something clean. Encouraging a second washing was a way for users to generate the suds they expected, with the bonus that they used more shampoo in the process. Nowadays, not only does “rinse and repeat” increase shampoo sales, it also increases sales of other hair products, since excessive washing can dry out hair, leading to the purchase of conditioners and other treatments. Of course, anyone who feels that washing twice makes her hair look its best should feel free to shampoo away. If she wants, she can even use more than the recommended dime-sized amount.
Oil Change Change-Up
The conventional wisdom says that we should change a car’s oil every 3,000 miles, but some experts say that might be too conservative. Auto manual recommendations vary between 3,000 and 10,000 miles, but the guys behind NPR’s “Car Talk” radio show recommend changing oil every 5,000 miles or so. According to them, “It may be too soon for many people and too late for a few, but for the vast majority, 5,000-mile oil changes will help your engine last to a ripe old age.” Changing the oil regularly is vitally important to prevent engine damage, but modern engines and oils have a bit more leeway than their older counterparts, so they can go longer between servicing. Synthetic oils, especially, resist breakdown for many thousands of miles. People who should consider changing more frequently include those who regularly tow or carry heavy loads, people who go through extreme seasonal climate changes, those who often make quick starts or slam on their brakes, and people with older cars.
The “Magic” in Your Fridge
Who doesn’t have an opened box of baking soda in his refrigerator to eliminate odors? The one currently sitting on my shelf says that the box should be changed out every month, but it wasn’t that long ago that the instructions were to change it every three months. So is baking soda a third as effective as originally thought? Maybe the company decided that changing the box every month as opposed to every ninety days would buy the CEO that Learjet a lot faster, because there’s no evidence-based reason for it to be changed so often. Baking soda is purported to neutralize odors by absorbing them, and although it has many household uses, some people don’t find it especially useful in the refrigerator, regardless of how fresh it is. If you’re someone who believes in the magic of Arm & Hammer, change the box as often or as infrequently as you desire, since it probably doesn’t make a difference either way.
