There are much better poison types to use in ORAS.
I would prefer Zubat or Tentacool to start with.
You can get Zubat very early in the game after you beat the first gym
You can get Tentacool either from a trade or after you beat the fifth gym
I will be including the sets for the final evolutions
Crobats set should be Poison Fang/Cross Poison, Acrobatics, Fly and any other move you want
Tentacruels set should be Surf, Sludge Wave, Blizzard and again, any other move you want
Hope I helped!