Toss in the wash with cold water. Air dry. Boom.
Terribly uncomfortable
"These shoes have no support and no cushion. I have nearly flat feet and these are too flat even for me. They are lightweight but the soles are so thin that you feel everything. When wearing the shoes, the bottoms of your toes rub in an uncomfortable way that eventually starts to burn. Also, I’m a true 39 and though I purchased the US equivalent of that - an 8. 5, they almost feel a touch too small. However, the next size up was entirely too large and flopped off my feet."