Mold HATES Vinegar
An old sailor taught me that mold and mildew hate vinegar! It seems that vinegar kills the spores, and inhibits regrowth. Vinegar is also completely safe for all wood finishes. After you winterize, clear shelves and make all teak areas available. Make a 3-1 solution of water and white vinegar. Rub all teak areas (shelves, corners, cabinets) down with a sponge and allow to completely dry. The boat will smell like you are making Easter eggs, but it quickly dissipates. After the wood is dry, use your favorite wood oil to bring back the luster (I use orange oil or Old English lemon oil). The vinegar solution is also safe for all areas (fiberglass) of the boat in terms of killing mold and mildew and light cleaning. If the problem is particularly deep in the teak, you may try the vinegar solution several times before you apply the oil. Good luck!