Putting two old towels on the bottom of the bathtub is a more important step – avoid the grill scratching the bathtub or your beloved big bath, then place the grill flat on the towel. Add hot water to the bathtub and let it immerse in the grill. Add a half cup of detergent and stir it a little to let the detergent spread. If it is a powder, stir it to dissolve completely. Just sit still, soak the grill for a few hours or even overnight. After soaking, the dirt on the grill is loose. At this time, scrubbing with a brush or sponge is quite simple. After scrubbing, rinse thoroughly with water and dry it to dry.