The odor is common with keshi that have been freshly drilled. There is some "matter" inside some of them that needs to dry out. Eventually the smell will go away. The string absorbs and holds the smell. Recommend you take the pearls off the string and leave them in the open to dry. How small are the pearls? If they are fairly large, you may be able to isolate the offenders, flush them with a syringe of 50/50 hydrogen peroxide and water, then let them dry. (This tip is from our forum member, Marianne!) Could take a few weeks, maybe less, maybe more, until the pearls pass the sniff test ~
Your new pearl is lovely, love that it is an enhancer!