Basically, the fibers should be able to lift the stray flecks of mascara without compromising any of your makeup (whereas a cotton swab dipped in remover can lift concealer and shadow with each swipe). Comments Hughes, a cotton swab “will just rub in the product, especially if you need to use makeup remover, you’re going to ruin all of the makeup you did.”
Another important caveat to mention here: Make sure the mascara has fully dried down before you try to whisk the pigment away. If you’re dealing with wet product, you’ll only smudge it further with the spoolie. Also, Hughes emphasizes a gentle pressure (“delicately buff,” she says), as you don’t want to pull or tug at the sensitive eye area–or, uh, stab your skin with the dry spoolie. Ouch.
If you have any mascara mistakes on the upper eyelids (where the skin is even more thin), Hughes recommends an even gentler hold on the spoolie. Of course, you should stop if it ever becomes painful, but if “you’re super delicate and the spoolie is soft,” you should be fine, she says in another comment.