So who should double cleanse their hair? Well, it all comes down to how much build-up you have on your scalp, your personal washing schedule, and your hair type.

One thing to note: You may be accumulating build-up without even realizing it, especially if you frequently use products like gel and dry shampoo. But aside from the build-up, there are generally two types of people who are best suited for double cleansing: those with straight hair and those who wash occasionally.

“Straight hair tends to get oily more quickly, so double cleansing can be more beneficial for maintaining a clean and healthy scalp,” says Misseri. What’s more, removing all the dirt and oil from the scalp will help those with straight strands get more volume at the roots (a win-win).

For those who wash their hair once or twice a week, double cleansing can also work because the longer you go without cleansing, the more build-up you will have.

On the other hand, “for those who wash their hair every other day, I would recommend sticking to once most of the time,” explains Misseri. The same rules apply to those who cleanse their skin daily.

Those with curly or textured hair should also be careful: “Curly, wavy, and frizzy hair tends to be drier, so it’s important to avoid overwashing and stripping hair of its natural oils,” Misseri says. “Double cleansing may not be necessary for these hair types unless there is significant build-up.”

If you wash your hair every day and still see greasy roots, you may want to consider changing your shampoo before opting for a double cleanse. “A great shampoo will do a lot of the work for you—it’s not so much the manual cleansing as the product you use to cleanse your hair and scalp,” Hans explains.

However, any hair type can benefit from an occasional double cleanse when it comes to heavy build-up. Or you can always grab a clarifying shampoo or scalp scrub to achieve a deeper clean every few weeks.