last night when i posted the jolteon i had said it was impossible without an emulator, but thinking about it now it probably is do-able. like you said, just loads of practice. you might want to do it on an emu first and count the amount of time between hitting A on the "xxx warped to the high link!" and when the mtrng reseeds. then you'll know how much time to give between pressing a and hitting it on a real cart.