Loofah, the netted bathing scrub that comes in an array of colours, sizes and levels of puffiness, contains bacteria grown from you skin cells.
Though, the benefits of exfoliation are frequently trumpted, an estimated 98 percent of dermatologists would warn you against using them.
It gets rid of our dead skin cells, allegedly helps boost circulation and, without wanting to sound too much like advert, is meant to reveal softer, smoother skin.
By using them to exfoliate, dead skin cells nestle and get trapped in the copious amounts of netting. "Then," Knight explains, "you put them in this environment in the shower that's warm and moist and gross, and it's a setup for bacteria, yeast and mold to grow in the puff."
In particular, if you use these puffs after shaving, all that grossness can get into any nicks, which may lead to infections and bad skin.
However, if you're not prepared to ditch the puff then scientists suggest rinsing it off thoroughly after each wash and making sure it can dry off properly away from the dampness of a bathroom. Make sure you also replace it every three to four months, unless it smells a bit funky or has gone a bit mouldy. In which case, bin it immediately.