Diagnosis
The deck is vulcanized rubber and the handles are silicone. Both can be cleaned, but moisture must be kept away from electronic junctions.
How to Fix It
Use a cloth dampened with water and a mild soap. Wring it out so it is damp, not wet. Wipe down the rubber deck, stem, and handlebar grips. Immediately dry all surfaces with a separate, clean, dry microfiber cloth. Do not spray or pour liquid directly onto the scooter.
If That Didn't Work
For stubborn stains on the deck, use a dedicated rubber cleaner or isopropyl alcohol (70%) on a cloth. Test on a small area first. Avoid all-purpose cleaners or solvents which can degrade the rubber and silicone.
Heads Up
Never submerge any part of the scooter. Avoid getting moisture in the charging port, around the power button, or at the base of the stem where wires pass through. Water ingress there can cause controller failure and is not covered under warranty.