Ugh, she was hell. My suggestion would be to think about the move(s) that you hate so much: Volt Switch. According to Serebii, the gym leader has 2 emolga, with the set of Volt Switch, Pursuit, Quick Attack and Aerial Ace, and a Zebstrika with Volt Switch, Spark, Flame Charge and Quick Attack. Neutralise the 1st Emolga, and if she sends out Emolga 2, wait for the VS, then hit Zebby with a ground type move.
Oh yeah, go in the building. Clay has a Krookodile LV29:
Ability: Intimidate
Moves:
Crunch, Swagger, Torment, Bulldoze.
Just watch out for Torment. Stops you spamming Razor Shell. Train up Oshawott to LV31 and Aqua Jet first time, Shell on the second.
Next is a LV29 Palpitoad:
Ability: Swift Swim.
Moves:
Muddy Water, Aqua Ring, Bulldoze, Bubblebeam.
Easy bait for a grass type. Just smack it hard. Easiest poke to take down in my opinion.
Afterwards, its a LV31 Excadrill:
Ability: Sand Rush
Moves:
Slash, Rock Slide, Bulldoze, Hone Claws.
The only thing to worry about is not letting Excadrill get more than 2 Hone Claws under its belt. If that happens, you're done for. I learnt that the hard way :(.
Clay also has 2 hyper potions. Good Luck (Not that you'll need it) !