Your best buy is Zodiac Protect... A restorer... And then.. Believe it or not a sun milk.. Uv protector. A two bottle kit.
Before
After... But photo just shows grime removed not the second bottle of a UV protector... My Zodiac Classic looks like new after 220 km of cruising! Highly recommended. After UV protector is applied the boat shines... Keeps material supple... One a year.
Should avoid using other cleaning agents as some may deteriorate the tubes. I did whole boat.. Under inside and tubes... Bottle says tubes. But though it can do any harm.