It was a good activity to do while Grandma was here - she came to help out because the boy's babysitter is out of town. We're excited to have her here next weekend too! Hooray for Grandmas!
We used a sparkle egg coloring kit - it had sparkle glue that was painted on and the color packets had a bit of oil in them that created a swirling effect. The sparkle glue probably wasn't worth it - there was only a small amount in the kit. I wonder if you could pull off a similar effect by just painting the egg with glue and using your own glitter. The swirling effect could definitely be created with a strip-down dye kit - just add a couple of drops of oil to your cup of dye. Re-dip in a second color for a multiple color effect.
And the best part is that Peter is enjoying eating the eggs too!