B..
The lady at Tiffany told me I could soak them in water with a squirt of gentle dish soap. (Think organic brands.) Also, she said to scrub gently with a soft toothbrush.
I do have free ring cleanings for life with my ring, but they send it and it takes a week or so to get it back. I have never done it, because the dish soap really works for me. I don't have a loupe, but that might be a good idea. My ring is one of a kind and thoughtfully designed by my husband. I would be devastated, if I lost a stone.