If you have a solid skin-care routine packed with toners, spot treatments , and oil-free moisturisers but still manage to end every day with a cystic pimple, it might be time to look for another culprit. Besides stress and hormones, one primary suspect could be your dirty makeup sponge. While the texture of those beloved, egg-shaped tools blends foundation, concealer, and even powder seamlessly, it can also easily hold a lot of gross bacteria.