Teak brightwork--the unpainted teak woodwork on a boat--makes a gorgeous accent or even an attractive deck on the right boat, but untreated teak stains easily. When a guest spills a drink on your untreated teak deck or other untreated teak, like the chart table, the wood's silver-grey patina will absorb the liquid, and a stain will result. Removing these stains involves a bit of elbow grease, some materials that you may already have around the house and a bit of teak oil to restore the finish and protect the wood.
Apply bleach to the stained teak with a paint brush or clean rag. At least one bleach manufacturer produces a "thickened" bleach that will lay on the surface rather than running off.
Scrub the bleach into the stain with a rag or a plastic scrubbing pad. The stain should begin to disappear as soon as the bleach makes contact.
After the stain has been scrubbe,d out, rinse the teak with water. Don't soak the teak; use only enough water (Soak a rag in clean water and wipe the teak down; if you can't, put running water on it because of its location.) to remove the bleach from the wood. Allow the teak to air dry completely.
Apply teak oil to the wood's surface. You can't add "too much" teak oil on the wood because it can only absorb a certain amount. Allow the teak oil to dry, and wipe any excess off with a clean, dry rag.
It'll cost you that silver patina, but treating your teak with teak oil or varnishing it with a natural varnish or a polyurethane varnish will prevent spills from becoming a problem.
Teak oil is a drying oil. As it drys on a rag, the drying process generates enough heat to cause a fire. When you're done with rags or paint brushes or whatever tool you use to apply the teak oil, dispose of rags in a metal waste container with a top to prevent a fire from "spontaneous combustion."