UPDATE
shortly following azalea town, I caught an oddish in ilex forest, which thankfully came with sweet scent. I taught it cut so I could move through the trees, and trained it up on the trainers just north of ilex forest and in the underground in goldenrod. after much training, oddish learnt mega drain and evolved into gloom, so it became much more powerful. :D
we were ready for whitney, who was obviously a pest. clefairy was no problem. krabby took the lead and used metal claw which boosted it's attack on the first go, and on the second turn, clefairy was knocked out. miltank though... ugh. attract + stomp combo as per, which was terribly annoying as both krabby and gloom are males. -.- eventually I scored a critical hit with vicegrip when miltank was down to half health and won. :D
TEAM
Krabby - Level 22 // Mud Shot, Bubblebeam, Vicegrip, Metal Claw
Gloom - Level 21 // Mega Drain, Sweet Scent, Cut, Acid