sealing organics

[http://users.livejournal.com/anam_cara_/]

Ok, so I want to make a bracelet similar to the necklace found here:
http://www.javajewels.com/

I even found a great little coffee cup on a saucer charm to incorporate.

Here's my question though- how best to seal the beans? I initially coated them with Mod Podge, but when I drilled the holes, it peeled off. So, should I dip them in shellac or polyeurthane (or are those just two names for the same thing?) or will spray varnish do the trick? I know there was a post about dipping gummy bears (or was it conversational hearts) in polyurethane, but I have spray on hand, but as it's for a gift, I don't want to skimp if that's not recommended. Oh, and I also have a bit of that two in one stain/varnish for wood, perhaps that would work?

Another coffee related question- anyone know how to make a homemade version of Java Logs?