Going back to the COLEAN, this is something I have used and wouldn't use anything else now!
It is very expensive (UK) and not easy to apply. Also slowly goes off once you open the tin but using a heat gun before putting the lid on helps a bit.
It has lasted for years (outside) and is just starting to let a bit of water in after about 5 - 6 years.
High gloss finish which I like and very flexible. It is a bit like plastic coating your wood but is still breathable and flexible.
The extra effort is worth it for the results and not having re-do it every year