What works best to clean the non-skid surface?
Regular washing with a mild soap and a little elbow grease, will go a long way towards keeping the non-skid deck looking good. If the surface requires more than mild soap, use household products like Comet or Snobol. While there are some products which claim to protect a non-skid deck from stains and oxidation, many of them contain chemicals which create their own problems and are nearly impossible to remove if you are not happy with the results. Important: Unlike most gelcoat surfaces on a boat, it can be dangerous to wax a non-skid surface. Wax surfaces become very slippery when wet.
