Dry cleaning isn't dry.

You thought it was, didn't you?

It's not.

They call it dry cleaning because it doesn't wet your clothes with water the way you washing machine does. But it still uses wet chemicals to clean fabrics. Those chemicals can be pretty toxic.

Which is nothing new.

For as long as dry cleaning has been a thing, we've known it's pretty bad for us.

So you'd think maybe we would have done something about that by now.

The good news is: we have!

The bad news is: everytime we come up with a promising new chemical, we discover some new problem with it.

But researchers are finally getting close to identifying that elusive substance that can remove grease stains, not poison the neighborhood, and clean up dry cleaning's reputation.

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Most of your clothes can be washed in a regular washing machine with good old soap and water, but if you have anything made of wool, silk, or suede, check the tag first. It might be dry clean only.

And if you've ever, like rolled the dice and thrown your dry-clean-only clothes into the washing machine, you know how shrunken, discolored, and shapeless they can turn out.

Dry cleaning takes it a little easier on those special materials that can't handle the washing machine. The spin cycle doesn't whip your clothes around quite as hard.

Aside from being gentler, one of the big differences between dry cleaning and your laundromat is the cleaning solution.

The liquid that dry cleaners used has changed a lot over the last couple of centuries.

Back in the 1800s, before washing machines were invented, the first American dry cleaners would hand wash garments in tubs of gasoline or kerosene. Believe it or not, that go the stains out. And their wool clothes didn't shrink.

It worked through the power of polarity.. or lack of polarity.

The water we use for regular washing is polar. The two hydrogen atoms have slight positive charges, and the oxygen atom carries a slight negative charge. This makes opposite charges on opposite sides of the whole water molecule.

And water isn't the only polar molecule out there. The salt in your sweat is also polar, which we can use to our advantage because polar molecules dissolve other polar molecules.