Yea, my bad, I forgot one slot must be used for Pursuit. So maybe 3 Atks + Slack Off @ Life Orb then ;d
But yea, another way to use Slaking is simply to use Choice Band. Usually if you're ahead of the headcount, you can sac your mons to bring in Slaking to kill a mon, rinse and repeat, and you can win by always being ahead of a kill. Slaking has amazing physical bulk, and can occasionally afford to stay in to take whatever hit without resorting to saccing teammates. Ghost-busters are obviously good teammates, and Fighting-types are great for busting Umbreon & Steel-types. Heracross is particularly good since it can also double up in busting most Ghosts like Sableye. Other Protect users, such as Sharpedo and Yanmega can be a bitch, so make sure to have a good check for those, too.