Diamondelle has a coating of nanocrystalline diamond on its upper layer.  As such, it is chemically inert and very abrasion resistant. 

You can swim, shower, etc. with no undue concern.  Be sure to remove your jewelry when engaging in activities that may scratch or loosen the setting - i.e. rock climbing, gardening or other activities where you are likely to give your jewelry a nice whack or hard scratch.

Quick Cleanings:

Simply wipe your Diamondelle stones and settings with a scratch-proof cloth. No rinsing needed.

More Thorough Cleanings:

Use any standard home jewelry cleaner, or you can make your own cleansing solution by simply combining warm water and a small amount of dishwashing liquid (i.e. Joy, Palmolive, etc.).

Place your jewelry, one individual piece at a time, in the solution and allow it to soak for a few minutes - the dishwashing liquid will help dissolve body oils, which play a large part in trapping dirt (esp. rings). With an old toothbrush, gently(!) scrub the jewelry to break up trapped dirt.  Be sure to get the undersides of your stones, if possible.  Buildup on the underside of gems is what causes a dull grey look. After cleansing, rinse with water and pat dry. Diamondelle stones can also be cleaned using steam or ultrasonic cleaners. Keep your Diamondelle stones clean for peak brilliance.