Replace 3 with "waste all your mega snacks" to make the guide more accurate. Don't train it to Mega, that's hard. Just make sure that your pet can manifest all desired talents and train it until mega or failure, in which case hatch again.
You can use the talent order list on 101Central to see if the talents you wanted passed in a hatch. If not, don't train all, just hatch again. If you got the talent on the pet, train to adult. If you get things you want keep going, if not hatch again. You don't want to train to mega unless everything is good at the lower levels.