I bought the Starbrite combination cleaner and brightener here for the teak deck of my sailboat. The brightener doesn't seem to have much of an effect at first - but once the deck was dry you could see where the wood was light and where it still had a gray shadow (clean, but still grey). So works fine. Important GLOVES (the stuff etches properly) and wash the stainless steel and brass fittings well afterwards (stainless steel polish from the kitchen also helps here)
Complementary product in phase 1 to restore the original teak color. Beware of the coulures on dark hull, leaves big white traces .... So better to rinse the hull once the treatment of the finished teak.
Great!!! Before that use level 1 and then the brightener (teak cleaner 2) and the wood looks like new. Then the protection by the oil and the wood is well protected for 1 season (I speak now only for our terrace furniture, which are the summer over in the open air).
The medium premium teak cleaner eliminates fouling easily. But is only one part of a care series. In conjunction with the teak whitener and the tropical teak oil, I have achieved very good results. I will work on my cockpit as well as the complete teak deck with the products. From the fertility I would say cleaners and brighteners are enough for a 36er. I am not sure about the tropical teak oil and will order a pack as a precaution.
In contrast to the teak cleaner, the brightener has shown hardly any results for me. The wood has become somewhat yellowish due to treatment, but is hardly visible. So I think level 2 is unnecessary. For me level 1 (cleaner) and level 3 (sealer) are enough.