Have an 2003 40P with teak trim, for those we first scrub against the grain lightly with a soft brush and mild soap from tally, rinse and repeat, if that does not do it, move up to a mild teak cleaner, we like the powdered ones and repeat, if that still does not do it a teak conditioner is what we have used for the really moldy or dirty spots, always against the grain with softest deck brush you can find… works for us, good luck, Ive heard a salt water scrubbing is also beneficial but we sail in brackish water.
The membership association for owners of Dufour Yachts