Due to the mechanics of Emeralds RNG, Hidden Powers can be borderline impossibly difficult. It's very simple to use, but advances at 60+ frames per second! Low chance females aren't as bad though.Do you do RNG legen captures too? ;D I understand you might not..! lol Would you have anything against breeding Hidden Powers? Or low chance females? I've got plenty of need-to-be-breeds though so you decide difficulty and I'll pay accordingly. =P
If you want them for useage there's many special tutor moves that can be used. My personal favourites are the Softboiled Clefables and Counter Gengar (both of which I have already bred and ready, essentially exclusive to my shop).