Using essential oils on beads for bracelets etc. how to use them safely? dilute?

Starting a business infusing beads with essential oils and just need tips for how to use them.
I saw a store on ebay that sold them but called them bla fragrance oil and bla carrier oil. So I was wondering which to pick.
Emailed the owner and they said that fragrance oils are for a diffuser and essential oils need to be diluted. Would you say this is the case in our situtation where the would just be a couple of drops put on the beads and left to dry?
One more question: we're looking for other nice aromas such as watermelon and I'm guessing it's not possible to use those near the skin as they're not essential oils and are just for diffusers. Any suggestions?