Skylights are products practically maintenance free in the sense that their volume shape does not allow dust layer to stay on for long. Fairly strong wind and rain self-clean the glazing.
However, dust and atmospheric pollution –number one enemies of translucent products- are cleaned with a soft cloth or leather and a solution of lukewarm water with soap or mild detergent. Lots of water to wash out and drying with same cloth completes a temporary cleaning.
Never use dry cleaning, since it causes scratches and increases static electricity.
Use of alkaline, acetone, benzene, etc can gradually destroy your glazing.
A complete list of impact chemicals is available.
Skylights are products delivered and assembled according to requirements of ISO 9001 and certified according to EN 1873. They are items for a lifetime, unlimited, could be said, if glazing is glass. A 10 year guarantee exists for the construction and a 1 year one for the mechanisms, if correctly installed.