The video title most likely refers to the standard numbered compartments found in a washing machine's detergent drawer. While modern machine labels can vary, the following guide explains the universal purpose of slots labeled 1, 2, and 3 . Washing Machine Drawer Guide
Do not exceed the "MAX" line, as this can cause the softener to siphon out too early. Essential Laundry Tips SS0 1 2 3 laundry.mp4
Use this during the final rinse cycle to soften clothes or add fragrance. What to add: Liquid fabric softener or conditioner. The video title most likely refers to the