Does anyone have experience with cremation jewelry?

I was finally able to obtain some of Tigh’s ashes, but I don’t just want them to be put up somewhere. I want him with me, as weird and/or stupid as that may seem to some. That said, I was thinking about getting a cremation necklace, such as something like this.

You put the ashes in by unscrewing the top. The site that carries this particular necklace suggests using modeling glue or epoxy around the seal to make it permanent. Would that work? It kind of makes me paranoid to think that the top might come off at some point.

Do you suggest these?