How to make old easter eggs into egg shakers

I got this idea after being in the instrument section of the toy store - egg shakers, they are called ocarinas, they are like maracas with out the handle.

So this is the easiest thing - just add some rice (different kinds), lentils, dried chick peas, rice crispies or whatever you want into a plastic egg and glue closed. I then taped them up so they could be played with right away. But hours later I took the tape off and the glue still didn't hold, so I need to figure out what glue works best on plastic - any ideas?

Even with the tape left on they are fun to play with. We added different things in each one and it's neat to hear the different sounds they make.