That's technically your opinion, but here is what I recommend:
Hurricane
Firstly, this is what Bulbapedia mentions
Hurricane deals damage and has a 30% chance of confusing the target. Hurricane can hit non-adjacent targets in Triple Battles.
Hurricane can hit Pokémon during the semi-invulnerable turns of Fly, Bounce, and Sky Drop.
When used during rain, Hurricane bypasses accuracy checks to always hit, unless the target is in the semi-invulnerable turn of a move such as Dig or Dive. When used during harsh sunlight, it has an accuracy of 50%.
So what I would recommend is having a Pelipper, as your Pokemon to set up rain using it's Drizzle ability. Then you can have perfect accuracy for Hurricane. And if Hurricane having perfect accuracy is not good enough, the good things about using Pelipper is the fact that it has Drizzle, also now you have a Water type member on your team, so you can also counter Fire types.
Air Slash
Firstly, this is what Bulbapedia mentions
Air Slash inflicts damage and has a 30% chance of causing the target to flinch. It can hit non-adjacent opponents in Triple Battles
It is definitely a good move for Flinching with the high chance, but the downside to this is that Frosmoth's base speed is 65, which means that you would have to set up a Trick Room to be able to go first, and having 95% accuracy is definitely not good.
Overall, I would recommend Hurricane over Air Slash
I've hoped I've helped!
