Ash's Dracovish no longer uses Fishious Rend? Why?

I knew that Ash's Dracovish use Fishious Rend one time in the only one of the Journeys episode, and I thought that Ash should've commanded Dracovish to use Fishious Rend more often against as many opposing wild and Trained Pokémon of their weaker defending types just that would help that guy get as stronger as possible? I wonder why Dracovish no longer uses Fishious Rend in other episodes, not even for the second or later times?