3. It is Oil Soluble
Salicylic acid is an oil soluble. This means that it is able to penetrate into the pores that line the face.
If this doesn’t immediately make sense to you, then think about it this way: when you go to wash up the dishes, if you have anything that is covered in a lot of fat, then you will find that it doesn’t easily wash. Rather, the fat gets stuck in the bristles of your washing up brush, and it coats the rough side of your sponge. This is because fat is not easily broken down by the water – in fact, it can be used to create a kind of seal.
Unfortunately, the fact of the matter is that your skin is also covered in a thin layer of fat (oil). This also fills up your pores. So when you wash, you are washing just the surface of that fat, and you’re not able to completely remove the dirt and grime.
Keeping all of that in mind, it follows that water alone isn’t going to be very effective at cleaning the inside of fat-filled pores. And the same goes for any other product that isn’t fat-soluble.
And that’s why it’s a really good thing that salicylic acid is.