Showering with gold-plated jewelry might cause the gold coating to wear away completely, therefore you should avoid doing so. Washing your hair with a golden shampoo may not be a good idea either because the chemicals in such shampoos could possibly lead to staining of the hair. If you must use a gold-plated item in the shower, then at least use a plastic or glass shower cap to cover it. This will prevent any water from getting in contact with it and thus prevent any tarnishing. Gold can be worn in the shower if you like the look and feel of it on your skin. However, because gold is so precious, I wouldn't recommend doing so more than once or twice a month otherwise you'll be putting yourself through a lot of pain just to look pretty.