Accessorize with stainless steel. I bought a pair of Axsmar stainless steel bracelets for the wife, with the locking feature, but modified so that it can be double locked (two keys required to open). Expensive, but they have been a lot of fun so far. Check of the 'Something just Clicked' set for some pictures.

We recently bought a padlocked Tiffany bracelet, for everyday wear when she is in or out of the house.