There isn't a problem getting gold plate wet it's a fallacy .The best way to clean gold plate is with warm water and a mild hand soap , then rinse off with warm water and thoroughly dry . The gold plate oxidises or changes colour through sweat , the chemicals in skin lotions etc , or from the effects of perfumes . The best way to care for gold plate is to gently wash with a mild hand soap and dry after every wear to prevent this oxidisation . I definitely wouldn't put anywhere near a Cape Cod cloth . You could try warm water and soap , or remove the bracelet and try a 'baking soda bath' . To do this get a sheet of what Brits call 'tin foil' or 'aluminium foil ' the stuff you use for baking , and line a suitable bowl . Then add warm water , and large spoon of baking soda , then stir it to agitate the baking soda . Then place the bracelet in for 10 minutes , and the chemical process in the bath should lift the sulphur from the gold plate which causes the oxidisation . It could all be in vain ,due to the gold plate being contaminated in the plating process . When plating stainless steel you have to apply a nickel based activating solution to the steel prior to gold plating
So it's a total fallacy that you shouldn't get a gold plated watch wet ! You shouldn't swim in sea with it , or in a chlorinated pool definitely ! However the way you SHOULD clean gold plate is with warm water and a mild hand soap , then dry thoroughly with a soft cloth . There are two ways gold plate discolours enviromental conditions , and poor application of the plating ( or both ) . Enviromentally oils in your skin , chemicals in lotions you use , hair products on hands, perfumes/aftershaves can oxidise the gold plate .As can harsh cleaning chemicals, degreasers like washing up liquid , also as above contact with salt , chlorine etc . After every days wear you should at least wipe the watch over with a soft microfibre cloth to get rid any thing that could of got on the surface of the watch . Even better is to give it a light clean with warm water , and soap then dry as above . It may seem extreme to do that every day , but there no need to saturate the watch . You can apply soapy water with a cotton bud , then dry with a microfibre cloth . Though it's pretty easy to soap up your hands , then soap up the bracelet , rinse under a warm tap , and dry .As far poor application that is a much bigger problem ! The steel has to be very clean and smooth prior to plating , and needs to have a nickel based activation fluid applied for the plate to adhere .If this is done poorly dirt or nickel can contaminate the gold plate and begin to show through .It can also contaminate the copper in the ROSE gold plate which will then verdigris and discolour ( yellow is the only naturally occuring colour of gold, rose gold has copper added to it which gives the metal it's rose colour) .
You could firstly remove the bracelet and give a good clean in a bowl warm soapy water , then dry . This might get the discolouration off , but looking at the watch i doubt if it will .The second method is to give it a baking soda bath . To do this line a bowl with tin foil ( aluminium foil) used for baking , fill with warm water ( not too deep enough to cover the watch and agitate the baking soda) , add a large spoon of baking soda , and stir to agitate . Then place the bracelet in bowl for 10 minutes , and the chemical process going on in the bowl should pull the surface discolourisation from the bracelet which is sulphur, and attract it to the foil which will go black . Then clean with soapy water , and thoroughly dry . If neither of these methods work , then the plate is as i supect contaminated and beyond home cleaning . I guess then you'll need to stick on a Rubber B or source a new replacement bracelet .