Tarte emphasEYES Waterproof Amazonian Clay Brow Mousse has become stiff and dry and you're contemplating throwing it out
Use a wooden stir stick or the handle of a small eye brush to stir the brow mousse. This reactivates the clay, moistening the product and returns it back to a fluffy, mousse-like texture.
I've not tried this trick on any of Tarte's other Amazonian Clay products, such as gel liners, cream eyeshadows, etc. But if you have one that's dried out, before throwing it out, give it a try!