Question says it really. They are both two turn attacks, which sucks.
Any good ways to use them in competitive battling?
It sucks that once AGAIN GameFreak put a cool Idea with a huge con.
The only good way is really to use a Power Herb.
That will require no set up, just an all out attack.
But you may argue that is not utilizing it as a pokemon losing an all important scarf or band.
IMO its not worth trying and its just another con like Sky Attack.