Start with a tag board egg cu out
Add strips of tissue one color layer at a time
Spray with a 4:1 water / vinegar solution.
Peel off the layers of tissue and discard. Use plastic gloves to keep fingers from staining.
Try it on a real hard boiled egg but don't eat it ! Try this technique on an egg shell after the content has been removed by the pierce and blow out method.
The technique looks very aged and muted. Dust it with spray glitter if it's too unconventional.