How Do You Get A Full Egg Chao

Give any chao it's OWN broken egg shell after giving the chao a few skelaton dogs and it will put it on. Now reincarnate the chao twice with the shell on the whole time and after the second reincarnation, it will be a full egg chao(I think). A lot of people say you can only do it with some sort of cheat but I'm pretty sure what I just said works. Good luck. I am actually trying it right now.