1、 Potassium permanganate and acetic acid. The method is to first dissolve a small amount of potassium permanganate in water, and then put the swimsuit to be rinsed in. It should be fully soaked, and after soaking for 10 to 20 minutes, the swimsuit will turn dark red. Pick up the swimsuit and wash it with clean water; Dissolve a little more acetic acid in water, and put the swimsuit soaked in potassium permanganate into an acetic acid solution. The swimsuit will gradually change from dark red to its original color, and the stained areas will also be removed without damaging the original color. Sometimes this method can also be used when wearing yellow swimsuits.

2、 After diluting with 84 disinfectant, try soaking it slightly, but be sure to control the dilution ratio and soaking time. This is related to the location and degree of staining of the swimsuit, and it is best to bleach it several times. It is better to be troublesome than to bleach it too much.

3、 Add laundry detergent and detergent with a high content of anionic surfactants 1:1 to warm water, soak the contaminated area in warm water for more than half an hour, and then rub it with your hands. If it still doesn't clean up, put all the swimsuits in water at 50 degrees Celsius or above, add a small amount of laundry detergent to scrub, and use the fading of the swimsuit to reduce the color difference when dyed.