seeing how there's a new fad for using ditto as a lead, I trained a new smeargle to try a new strategy:
Lenny
item: berry juice (doesn't matter what he's holding really)
Rest
worry seed
curse
baton pass
Since any ditto used in battle will have
imposter, they'll almost always use worry seed after noticing rest, while smeargle will uses a worry seed of his own. then he'll baton pass his worry seed to regigigas, removing his slow start and making him immune to sleep, while no matter what the other guy does, he'll probably get paralyzed by regi's thunderwave or return stomped.