I have three exterior teak rails that were coated with 2 coats Cetol natural followed by 2 coats Cetol gloss. It held up for six years in Gulf Coast sun, humidity, and heat. That's minimal maintenance in my opinion. It would have lasted longer if I would have sanded lightly and top-coated with gloss again about a year ago. Removed the rails and stripped last week; putting the final gloss coats now. Will reinstall this weekend.
The cockpit seating surfaces are teak veneer. I usually clean and apply 2-3 coats of Semco on the surfaces, annually, to prevent the teak from deteriorating; however, I don't want the slippery surface that would result with Cetol. Semco seals the surface and prevents water penetration. Much easier to apply as compared to Cetol; however, the down-side is that it isn't long lasting. It takes approximately one hour to apply one coat of Semco. No need to tape, just wipe away any brush marks on gelcoat with a clean paper towel or rag.