Anyone who's ever bought a new electronic device or a pair of shoes will be all too familiar with those little "DO NOT EAT" sachets that come in the box. Most of us have a vague idea that they're somehow keeping our products fresh, but we toss them as soon as the box is open without a second thought.

As it turns out, that's entirely the wrong thing to do. As Eames Yates reports for Business Insider, these free sachets of dessicant can be used for a whole range of life hacks that can save you time, energy, and money. And we're never throwing one out again.

The sachets contain silica gel - little balls of silicon dioxide (pictured above), which is porous and will quickly absorb moisture from its surroundings. It's actually the same stuff as what's used in some types of 'crystal' cat litter.

Despite the dire warnings on the packet, the little silica beads don't really tend to be poisonous, although some toxic chemicals could be added in the mix. The biggest danger, however, is a potential choking hazard, so you should keep them away from kids.

But if you save up a pile of silica gel, it can be incredibly useful. Not only do these sachets keep your purchases dry and fresh in the box, they can also come in handy whenever you need to dry something out. Here are some of their life-changing uses:

1. Save your wet phone

Dropped your iPhone in the toilet again? Forget rice, according to Business Insider, these sachets are far more efficient at sucking up moisture. Just leave your phone switched off in a jar full of them overnight, and they should dry the device out thoroughly.

2. Defog your windshield

Never wait for your windshield to clear up in the mornings again - instead, simply place a few of these bags under your windshield on the inside and they'll keep it dry and clear regardless of the weather.

3. Extend the life of your razor blades

Any shaving aficionado will know that moisture is your razor's worst enemy, with damp blunting your blades before their time. Business Insider recommends keeping your razor in a tupperware container with a few of these silica gel bags to keep them sharp for longer.

4. Keep your gym bag fresh

You can avoid mould and bacteria colonising your sweaty gym gear by adding a couple of these sachets to your gym bag. They should also help with the odour.

5. Protect your old photos

Many of us store our old photos in attics, cellars, or other equally damp places, which can lead to the pictures sticking together and deteriorating over time. Keep them in a box with a few silica sachets and it should keep them dry and intact for longer.

Seriously, we had no idea, and we'll never take these free goldmines for granted again. Check out the Business Insider video for more on how to use them. The regret is real.

A version of this story was originally published in March 2016.