Can poochyena use rock smash

No, Poochyena cannot learn Rock Smash in the main series Pokémon games. Rock Smash is a Fighting-type move that is typically taught to Pokémon with the ability to break rocks and obstacles in the game world. Poochyena, being a Dark-type Pokémon, does not have the physical strength or capability to use Rock Smash in battles or to interact with environmental obstacles.