You can clean your Body using a cloth dampened with water. If water is not enough to clean it, you can also use crystal vinegar.
Important: Do not, under any circumstance, use any solvent to clean your Body.
https://support.withings.com/hc/zh-cn/sections/6212630854033-Body
https://support.withings.com/hc/zh-cn/sections/115001378708-Maintenance