I find that the most effective way is simply clean your jewelry with a dry soft cloth and store in a small zip lock bag. Also, I use warm water and a mini toothbrush to very gently rub gold filled chains.
Most of Jadel jewelry pieces are gold filled, and water friendly but still I wouldn't recommend showering with jewelry on. As shampoo and body cleansers etc make jewelry dull.
Most importantly, do not go into swimming pool with jewelry on. Chloride and other chemicals will affect the color of jewelry. It happened to me. (smh)
Always store your gold plated jewelry in a pouch, a zip lock bag and a box, will prolong the life of the finish.
Use a dry soft cloth to clean your jewelry very gently after each use.
Don't get them wet!