15inch Shower Head Built in Ceiling Shower with Led Lights Stainless Steel Bluetooth Speaker Built In

Method 1: 

In order to keep the surface of the shower clean, use a soft cloth, rub the surface with the flour, and rinse with water to keep the surface smooth;

Method 2: 

Brush the surface of the shower with a toothbrush and a toothpaste. Brush it for 3 minutes, rinse with water, and dry.