Salt is loaded into the conditioner compartment. You need to add a little less than 1 tbsp. If there is more salt, then it may remain on the clothes, which is not critical. Adding it to the conditioner compartment allows you to rinse your laundry with a salty solution. This helps preserve the color of the fabric. It washes out less and remains bright and saturated longer. The most important thing is that salt helps rinse out the washing powder.
After washing with it, the laundry smells less of fragrances, and there are no white streaks left. Also, clothes washed with salt dry faster.