Yup! I completed the dex in Blue and Yellow. I did use the Mew trick multiple times. :D
Haha if your nephew is young, he would restart the game many times anyways.. I had a neighbor, like age 6, who said he got all 3 starters. I look in his party and pc and he only had one. ummm you realize you're deleting your progress dude, lmao.
here ya go!
You completed the Blue version dex??? :o Did you get Mew, too? c: I remember getting Mew in my Red version from that glitch on how to get it. XP
My Gold version's battery died a few years ago; I ended up giving it to my nephew along with my Gameboy Color. XD;
I ended up erasing that Emerald file. D; I don't have my Pearl version anymore; I let my friend in AZ borrow it, and I've been unable to get it back. :I Doesn't bother me though. XD;