Doesn’t need to be washed before each use!
When the mask is visually dirty:
    • Soft Wash by hand (max 30 to 40° C or 86 to 104° F);
    • Don’t iron;
    • Dry in open air;
    • Don’t wring

    There's no need to wash it every day just take it off and put it in a dry, ventilated area!

    For more details see here