don't bother, those dogs all have crap IVs, regardless of anything you do.
(waves Colosseum Disk in hand) Good thing I have this... I guess you have to wait til HGSS then.
SRing a Modest Mewtwo with decent IVs is insanely difficult, that's about it.
However, that Spoink just WON'T swarm for me, I can't count how many times that it swarmed Farfetch'd, at least 8 times in the 20ish tries. I eventually broke down and caught and Pal Park it, argh.