When cleaning mold and mildew stains from teakwood, you can use a combination of bleach, soap, and water. After cleaning it and you notice black spots, you’ll need to apply a different mixture. This time, instead of bleach, substitute it with ammonia.
Remember, do not mix bleach and ammonia because when combined, a toxic chemical is produced that can be fatal when inhaled.Scrub with the wood grain using a hard bristle brush and then rinse with water when finished. Let the teakwood dry before you use it.