Don't keep soaking. I've also been using milk foam to apply the mask. I put pure milk in the refrigerator and take it out when I want to use it. It's cold on your face. It is especially useful for people who have just finished sunbathing. I learned my driver's license some time ago and didn't take any sun protection measures. My face is sunburned. It will be much better if I go home and apply it. However, if milk is kept in the refrigerator for a long time, it will turn sour. You should pay attention. If it is sour, don't just pour it out.