Toss in the wash with cold water. Air dry. Boom.
Comfortable
"Soft, stretchy, and comfortable, even with my wide feet. Have only ever bought daily flats or pointed flats, so this was a gamble. I got the same size as the flats and they fit well. Sole of the shoe was exactly what I was looking for (completely flat with a little cushioning). Feet get a little sweaty, so maybe not as breathable, but very happy with them so far! Not sure yet how they’ll hold up to wear and tear or washing."