most jewelry experts will agree that you should not use anything other than mild dish detergent and warm water on your jewelry. When you DIY anything, you take the risk of messing things up. Common recipes call for toothpaste, baking soda, vinegar, ammonia, etc. and can potentially damage your ring’s setting. Your diamond isn’t going to be damaged by most DIY recipes, but your setting is a different story. Use DIY recipes at your own risk! This is what I have found works best for my rings.
DIY Jewelry Cleaner-nice foaming action. Worked awesome 1 T salt, 1T baking soda, 1 T dish soap, cup of water (heated 2 min in micro) bowl with tin foil (dont know why but that was what it said). Let sit for 10 min and rinse in cool water.