I wrote the article and if you read it you will see that it mentions temperatures and the amount of food that I give them as well as the supplementing and gutloading (which also plays a part in preventing them from producing eggs, IMHO).
I have taken veiled females that I have hatched and kept them as I have described and they have produced no eggs at all and lived to be over 6 years old. I have also taken some of them and made the necessary changes to make them produce eggs when I needed to continue my lines.